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Artículos de revistas sobre el tema "Redox economy"
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Burns, Noah Z, Phil S Baran y Reinhard W Hoffmann. "Redox Economy in Organic Synthesis". Angewandte Chemie International Edition 48, n.º 16 (17 de marzo de 2009): 2854–67. http://dx.doi.org/10.1002/anie.200806086.
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Kotha, Sambasivarao, Deepti Goyal y Arjun S. Chavan. "Diversity-Oriented Approaches to Unusual α-Amino Acids and Peptides: Step Economy, Atom Economy, Redox Economy, and Beyond". Journal of Organic Chemistry 78, n.º 24 (26 de noviembre de 2013): 12288–313. http://dx.doi.org/10.1021/jo4020722.
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Kotha, Sambasivarao, Deepti Goyal y Arjun S. Chavan. "ChemInform Abstract: Diversity-Oriented Approaches to Unusual α-Amino Acids and Peptides: Step Economy, Atom Economy, Redox Economy, and Beyond". ChemInform 45, n.º 12 (6 de marzo de 2014): no. http://dx.doi.org/10.1002/chin.201412239.
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Guo, Sheng-Qiang, Hui-Qing Yang, Ai-Lian Wang, Yu-Zhen Jiang, Guo-Qiang Xu, Yong-Chun Luo, Zhao-Xu Chen y Peng-Fei Xu. "Divergent Ritter-type amination via photoredox catalytic four-component radical-polar crossover reactions". Green Chemistry 23, n.º 23 (2021): 9571–76. http://dx.doi.org/10.1039/d1gc03048e.
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Giovannitti, Alexander. "Redox-Active Polymers Designed for the Circular Economy of Energy Storage Devices". ECS Meeting Abstracts MA2023-02, n.º 4 (22 de diciembre de 2023): 505. http://dx.doi.org/10.1149/ma2023-024505mtgabs.
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The decarbonization of the transport and energy sector will accelerate the demand for electrochemical energy storage devices. While past and current research efforts strongly focused on improving the performance of cells (energy density, power density, and stability), little attention has been paid to how these devices are recycled after their end of life, leaving the recycling of devices as an afterthought. Thus, to limit the accumulation of electric waste and the depletion of important raw materials for energy storage devices, there is an urgency to develop a circular economy for materials and integrate recyclability in device architectures. In my talk, I will present a new concept where we applied chemical design strategies to intentionally develop redox-active materials for a circular economy.[1] We developed solution-processible redox-active conjugated polymers that function as binder- and additive-free electrodes with high stability in aqueous electrolytes, achieving >98% retention of the capacity after 500 charging/discharging cycles. The tuning of the local environment of the polymer further enables fast charging of micron-thick single-phase electrodes with cell voltages > 1.2 V in aqueous electrolytes. Finally, we demonstrate the recyclability of the devices, achieving >85% capacity retention after recycling (76 % retention after recycling the device twice). Our work is a demonstration of how material chemistry enables the development of a circular economy for electrochemical energy storage devices. [1] S. T. M. Tan, T. J. Quill, M. Moser, G. LeCroy, X. Chen, Y. Wu, C. J. Takacs, A. Salleo, A. Giovannitti, ACS Energy Lett. 2021, 6, 3450.
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Guo, Sheng-Qiang, Hui-Qing Yang, Yu-Zhen Jiang, Ai-Lian Wang, Guo-Qiang Xu, Yong-Chun Luo, Zhao-Xu Chen, Haixue Zheng y Peng-Fei Xu. "Organophotoredox catalytic four-component radical-polar crossover cascade reactions for the stereoselective synthesis of β-amido sulfones". Green Chemistry 24, n.º 8 (2022): 3120–24. http://dx.doi.org/10.1039/d2gc00224h.
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Organophotoredox catalytic four-component radical-polar crossover cascade reactions for the stereoselective synthesis of β-amido sulfones with high atom-, step-, and redox economy and excellent diastereoselectivity.
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Liu, Jia, Shuo Li, Raf Dewil, Maarten Vanierschot, Jan Baeyens y Yimin Deng. "Water Splitting by MnOx/Na2CO3 Reversible Redox Reactions". Sustainability 14, n.º 13 (22 de junio de 2022): 7597. http://dx.doi.org/10.3390/su14137597.
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Thermal water splitting by redox reactants could contribute to a hydrogen-based energy economy. The authors previously assessed and classified these thermo-chemical water splitting redox reactions. The Mn3O4/MnO/NaMnO2 multi-step redox cycles were demonstrated to have high potential. The present research experimentally investigated the MnOx/Na2CO3 redox water splitting system both in an electric furnace and in a concentrated solar furnace at 775 and 825 °C, respectively, using 10 to 250 g of redox reactants. The characteristics of all reactants were determined by particle size distribution, porosity, XRD and SEM. With milled particle and grain sizes below 1 µm, the reactants offer a large surface area for the heterogeneous gas/solid reaction. Up to 10 complete cycles (oxidation/reduction) were assessed in the electric furnace. After 10 cycles, an equilibrium yield appeared to be reached. The milled Mn3O4/Na2CO3 cycle showed an efficiency of 78% at 825 °C. After 10 redox cycles, the efficiency was still close to 60%. At 775 °C, the milled MnO/Na2CO3 cycles showed an 80% conversion during cycle 1, which decreased to 77% after cycle 10. Other reactant compounds achieved a significantly lower conversion yield. In the solar furnace, the highest conversion (>95%) was obtained with the Mn3O4/Na2CO3 system at 775 °C. A final assessment of the process economics revealed that at least 30 to 40 cycles would be needed to produce H2 at the price of 4 €/kg H2. To meet competitive prices below 2 €/kg H2, over 80 cycles should be achieved. The experimental and economic results stress the importance of improving the reverse cycles of the redox system.
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Becker, René, Saeed Amirjalayer, Ping Li, Sander Woutersen y Joost N. H. Reek. "An iron-iron hydrogenase mimic with appended electron reservoir for efficient proton reduction in aqueous media". Science Advances 2, n.º 1 (enero de 2016): e1501014. http://dx.doi.org/10.1126/sciadv.1501014.
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The transition from a fossil-based economy to a hydrogen-based economy requires cheap and abundant, yet stable and efficient, hydrogen production catalysts. Nature shows the potential of iron-based catalysts such as the iron-iron hydrogenase (H2ase) enzyme, which catalyzes hydrogen evolution at rates similar to platinum with low overpotential. However, existing synthetic H2ase mimics generally suffer from low efficiency and oxygen sensitivity and generally operate in organic solvents. We report on a synthetic H2ase mimic that contains a redox-active phosphole ligand as an electron reservoir, a feature that is also crucial for the working of the natural enzyme. Using a combination of (spectro)electrochemistry and time-resolved infrared spectroscopy, we elucidate the unique redox behavior of the catalyst. We find that the electron reservoir actively partakes in the reduction of protons and that its electron-rich redox states are stabilized through ligand protonation. In dilute sulfuric acid, the catalyst has a turnover frequency of 7.0 × 104s−1at an overpotential of 0.66 V. This catalyst is tolerant to the presence of oxygen, thereby paving the way for a new generation of synthetic H2ase mimics that combine the benefits of the enzyme with synthetic versatility and improved stability.
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Wu, Dezhen, Jialu Li, Libo Yao, Rongxuan Xie y Zhenmeng Peng. "An Electrochemical Ethylamine/Acetonitrile Redox Method for Ambient Hydrogen Storage". ECS Meeting Abstracts MA2022-01, n.º 1 (7 de julio de 2022): 136. http://dx.doi.org/10.1149/ma2022-011136mtgabs.
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Hydrogen is an appealing energy carrier that can potentially replace conventional fossil fuels in the development of a clean, sustainable hydrogen economy, which would resolve environmental problems caused by the combustion of the non-renewable resources while also meeting the rising demand for energy. However, hydrogen storage has remained a major roadblock in the hydrogen economy development. As a matter of fact, the state-of-the-art methods fall short of the 2025 Department of Energy (DOE) onboard hydrogen storage target of 5.5 wt.% under 85 °C and 12 bars. Herein we report a new, electrochemical ethylamine/acetonitrile redox method for efficient, high-capacity hydrogen storage under completely ambient conditions. The amine/nitrile redox couple is selected due to their moderate chemical polarity and relatively simple hydrogenation and dehydrogenation pathways, which would aid reaction activation and reduce the energy barrier. Electrochemical potential provides the driving force in CH3CH2NH2 dehydrogenation under ambient conditions, rather than high temperature and pressure that are typically required to thermally drive an endothermic process. We demonstrate an effective, complete cycle of CH3CN hydrogenation to CH3CH2NH2 for hydrogen uptake and CH3CH2NH2 dehydrogenation to CH3CN for hydrogen release at low overpotentials, using commercial Pt black catalyst in an electrochemical cell. The studied CH3CH2NH2/CH3CN system has a theoretical H2 storage capacity of 8.9 wt.%, well surpassing the 5.5 wt.% DOE target. This study offers a new, effective hydrogen storage strategy that can be extended to many other amine/nitrile redox systems and would help advance the hydrogen economy development.
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Zhang, Hao-Yuan, Tong-Tong Zeng, Zhen-Biao Xie, Ying-Ying Dong, Cha Ma, Shan-Shan Gong y Qi Sun. "Aerial Oxygen-Driven Selenocyclization of O-Vinylanilides Mediated by Coupled Fe3+/Fe2+ and I2/I− Redox Cycles". Molecules 27, n.º 21 (31 de octubre de 2022): 7386. http://dx.doi.org/10.3390/molecules27217386.
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In the past decade, selenocyclization has been extensively exploited for the preparation of a wide range of selenylated heterocycles with versatile activities. Previously, selenium electrophile-based and FeCl3-promoted methods were employed for the synthesis of selenylated benzoxazines. However, these methods are limited by starting material availability and low atomic economy, respectively. Inspired by the recent catalytic selenocyclization approaches based on distinctive pathways, we rationally constructed an efficient and greener double-redox catalytic system for the access to diverse selenylated benzoxazines. The coupling of I2/I− and Fe3+/Fe2+ catalytic redox cycles enables aerial O2 to act as the driving force to promote the selenocyclization. Control and test redox experiments confirmed the roles of each component in the catalytic system, and a PhSeI-based pathway is proposed for the selenocyclization process.
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Nguyen, Thanh Binh y Pascal Retailleau. "Redox-Neutral Access to Sultams from 2-Nitrochalcones and Sulfur with Complete Atom Economy". Organic Letters 19, n.º 14 (7 de julio de 2017): 3879–82. http://dx.doi.org/10.1021/acs.orglett.7b01766.
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Xiao, Jian, Shitao Yu, Liping Yu, Bin Qiu y Peizhen Dong. "Facile Synthesis of Spirocyclic Tetrahydroquinolines via C(sp3)–H Functionalization in a Cascade Redox Process". Synthesis 54, n.º 05 (25 de octubre de 2021): 1309–20. http://dx.doi.org/10.1055/s-0040-1720890.
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AbstractAn environmentally benign cascade redox process was developed for the efficient construction of the pharmaceutically significant spirocyclic tetrahydroquinolines via sequential SNAr/Knoevenagel condensation/[1,5]-hydride transfer/cyclization. This green transformation has the features of being catalyst-free, additive-free, operationally simple, and has high step- and atom-economy.
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Wang, Gang y Michael J. Krische. "Total Synthesis of (+)-SCH 351448: Efficiency via Chemoselectivity and Redox-Economy Powered by Metal Catalysis". Journal of the American Chemical Society 138, n.º 26 (23 de junio de 2016): 8088–91. http://dx.doi.org/10.1021/jacs.6b04917.
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Banerjee, Amrita, Ria Ghosh, Tapan Adhikari, Subhadipta Mukhopadhyay, Arpita Chattopadhyay y Samir Kumar Pal. "Development of Nanomedicine from Copper Mine Tailing Waste: A Pavement towards Circular Economy with Advanced Redox Nanotechnology". Catalysts 13, n.º 2 (7 de febrero de 2023): 369. http://dx.doi.org/10.3390/catal13020369.
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Copper, the essential element required for the human body is well-known for its profound antibacterial properties, yet salts and oxides of copper metals in the copper mine tailings are reported to be a big burden in the modern era. Among other copper oxides, CuO, in particular, is known to have beneficial effects on humans, while its slight nanoengineering viz., surface functionalization of the nanometer-sized oxide is shown to make some paradigm shift using its inherent redox property. Here, we have synthesized nanometer-sized CuO nanoparticles and functionalized it with a citrate ligand for an enhanced redox property and better solubility in water. For structural analysis of the nanohybrid, standard analytical tools, such as electron microscopy, dynamic light scattering, and X-ray diffraction studies were conducted. Moreover, FTIR and UV-VIS spectroscopy studies were performed to confirm its functionalization. The antibacterial study results, against a model bacteria (S. hominis), show that CuO nanohybrids provide favorable outcomes on antibiotic-resistant organisms. The suitability of the nanohybrid for use in photodynamic therapy was also confirmed, as under light its activity increased substantially. The use of CuO nanoparticles as antibiotics was further supported by the use of computational biology, which reconfirmed the outcome of our experimental studies. We have also extracted CuO nanogranules (top-down technique) from copper mine tailings of two places, each with different geographical locations, and functionalized them with citrate ligands in order to characterize similar structural and functional properties obtained from synthesized CuO nanoparticles, using the bottom-up technique. We have observed that the extracted functionalized CuO from copper tailings offers similar properties compared to those of the synthesized CuO, which provides an avenue for the circular economy for the utilization of copper waste into nanomedicine, which is known to be best for mankind.
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Rivera, Yago, David Blanco, Paula Bastida-Molina y César Berna-Escriche. "Assessment of a Fully Renewable System for the Total Decarbonization of the Economy with Full Demand Coverage on Islands Connected to a Central Grid: The Balearic Case in 2040". Machines 11, n.º 8 (27 de julio de 2023): 782. http://dx.doi.org/10.3390/machines11080782.
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The transition to clean electricity generation is a crucial focus for achieving the current objectives of economy decarbonization. The Balearic Archipelago faces significant environmental, economic, and social challenges in shifting from a predominantly fossil fuel-based economy to one based on renewable sources. This study proposes implementing a renewable energy mix and decarbonizing the economy of the Balearic Islands by 2040. The proposed system involves an entirely renewable generation system with interconnections between the four Balearic islands and the Spanish mainland grid via a 650 MW submarine cable. This flexible electrical exchange can cover approximately 35% of the peak demand of 1900 MW. The scenario comprises a 6 GWp solar photovoltaic system, a wind system of under 1.2 GWp, and a 600 MW biomass system as generation sub-systems. A vanadium redox flow battery sub-system with a storage capacity of approximately 21 GWh and 2.5 GWp power is available to ensure system manageability. This system’s levelized electricity cost (LCOE) is around 13.75 cEUR/kWh. The design also incorporates hydrogen as an alternative for difficult-to-electrify uses, achieving effective decarbonization of all final energy uses. A production of slightly over 5 × 104 tH2 per year is required, with 1.7 GW of electrolyzer power using excess electricity and water resources. The system enables a significant level of economy decarbonization, although it requires substantial investments in both generation sources and storage.
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Kang, Byungjoon, Zhenqian Fu y Soon Hyeok Hong. "Ruthenium-Catalyzed Redox-Neutral and Single-Step Amide Synthesis from Alcohol and Nitrile with Complete Atom Economy". Journal of the American Chemical Society 135, n.º 32 (5 de agosto de 2013): 11704–7. http://dx.doi.org/10.1021/ja404695t.
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Nazemi, Mohammadreza. "Electrochemical Redox Processes for Wastewater Treatment and Resource Recovery Using Single-atom Catalysts". Electrochemical Society Interface 31, n.º 4 (1 de diciembre de 2022): 36–38. http://dx.doi.org/10.1149/2.f03224if.
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This project will address the critical bottleneck in electrochemical redox processes (i.e., decreasing cost and improving efficiency) for wastewater treatment and resource recovery by developing cost-effective and selective electrode materials that can treat or valorize ROC for safe discharge or reuse. The overarching goal is to develop an electrochemical prototype to degrade a wide range of organic contaminants, minimize electrodes’ fouling and scaling, and recover valuable resources (e.g., metals and salts), contributing to achieving “pipe parity” and “circular economy” using small-scale and modular electrochemical water treatment systems.
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Feng, Jiajie, Zachary A. Kasun y Michael J. Krische. "Enantioselective Alcohol C–H Functionalization for Polyketide Construction: Unlocking Redox-Economy and Site-Selectivity for Ideal Chemical Synthesis". Journal of the American Chemical Society 138, n.º 17 (26 de abril de 2016): 5467–78. http://dx.doi.org/10.1021/jacs.6b02019.
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Wedenberg, Kaj, Gunnar Ronquist, Ulf Ulmsten y Anders Waldenström. "Energy economy of human uterine muscle strips under different in vitro conditions and its dependence on tissue redox potential". European Journal of Obstetrics & Gynecology and Reproductive Biology 62, n.º 1 (septiembre de 1995): 115–19. http://dx.doi.org/10.1016/0301-2115(95)02171-3.
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Kang, Byungjoon, Zhenqian Fu y Soon Hyeok Hong. "ChemInform Abstract: Ruthenium-Catalyzed Redox-Neutral and Single-Step Amide Synthesis from Alcohol and Nitrile with Complete Atom Economy." ChemInform 45, n.º 5 (16 de enero de 2014): no. http://dx.doi.org/10.1002/chin.201405070.
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Salar-García, María José, Víctor Manuel Ortiz-Martínez, Sergio Sánchez-Segado, Raúl Sánchez Valero, Antonia Sáez López, Luis Javier Lozano-Blanco y Carlos Godínez-Seoane. "Sustainable Production of Biofuels and Biochemicals via Electro-Fermentation Technology". Molecules 29, n.º 4 (13 de febrero de 2024): 834. http://dx.doi.org/10.3390/molecules29040834.
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The energy crisis and climate change are two of the most concerning issues for human beings nowadays. For that reason, the scientific community is focused on the search for alternative biofuels to conventional fossil fuels as well as the development of sustainable processes to develop a circular economy. Bioelectrochemical processes have been demonstrated to be useful for producing bioenergy and value-added products from several types of waste. Electro-fermentation has gained great attention in the last few years due to its potential contribution to biofuel and biochemical production, e.g., hydrogen, methane, biopolymers, etc. Conventional fermentation processes pose several limitations in terms of their practical and economic feasibility. The introduction of two electrodes in a bioreactor allows the regulation of redox instabilities that occur in conventional fermentation, boosting the overall process towards a high biomass yield and enhanced product formation. In this regard, key parameters such as the type of culture, the nature of the electrodes as well as the operating conditions are crucial in order to maximize the production of biofuels and biochemicals via electro-fermentation technology. This article comprises a critical overview of the benefits and limitations of this emerging bio-electrochemical technology and its contribution to the circular economy.
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Symes, Mark. "(Invited) Decoupling Strategies in Electrochemical Water Splitting". ECS Meeting Abstracts MA2023-01, n.º 36 (28 de agosto de 2023): 1950. http://dx.doi.org/10.1149/ma2023-01361950mtgabs.
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The storage of renewably-generated energy as hydrogen via the electrolysis of water is a fundamental cornerstone of a sustainable hydrogen economy. Conventional electrolysers usually require stable power inputs in order to operate effectively and safely and so may be unsuited to harnessing renewable power, which is often intermittent and diffuse. Decoupled Electrolysis (see, for example: Nature Chem. 2013, 5, 403-409; Science, 2014, 345, 1326-1330; J. Am. Chem. Soc. 2016, 138, 6707–6710; Joule, 2018, 2, 1390-1395; Adv. Energy Mater. 2020, 2002453; Electrochim. Acta, 2020, 331, 135255) has the potential to overcome some of the challenges surrounding electrolysis using low and/or sporadic power inputs (especially those related to gas crossover) as the decoupling of the two half reactions of water splitting allows the oxygen and hydrogen evolution reactions to be performed at different times, in different places and at rates that are not linked to each other. In this talk, we shall give an overview of decoupled electrolysis using liquid redox mediators and also explore the use of decoupling agents in other contexts such as redox flow batteries (Nature Chem. 2018, 10, 1042-1047) and electrosynthesis (Chem. Commun. 2018, 54, 1093-1096). Figure 1
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Kitamura, Masato, Kengo Miyata, Tomoaki Seki, Namdev Vatmurge y Shinji Tanaka. "CpRu-catalyzed asymmetric dehydrative allylation". Pure and Applied Chemistry 85, n.º 6 (15 de abril de 2013): 1121–32. http://dx.doi.org/10.1351/pac-con-12-10-02.
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Asymmetric Tsuji–Trost allylation is one of the key chiral technologies for construction of pharmaceutically important compounds because of the high utility of alkenyl-substituted products. Particularly, the dehydrative system using allylic alcohols and protic nucleophiles has started to attract the attention of organic synthetic chemists from the viewpoints of atom and step economy, environmental benignity, and operational simplicity. In this paper, two types of new chiral CpRu catalysts, which have been developed on the basis of redox-mediated donor–acceptor bifunctional catalyst (RDACat) concept, are presented. Complementary use of the chiral catalysts has realized the syntheses of a wide rage of carbocyclic compounds, saturated N- or O-heterocyclic compounds with high reactivity, regioselectivity, enantioselectivity, productivity, and generality.
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Tabuyo-Martinez, Marina, Ameya Bondre y Antoni Forner-Cuenca. "Towards Low Cost and Long Duration Iron-Air Flow Batteries". ECS Meeting Abstracts MA2023-02, n.º 8 (22 de diciembre de 2023): 3410. http://dx.doi.org/10.1149/ma2023-0283410mtgabs.
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The electrification of the energy economy necessitates the development of low cost and large scale energy storage technologies that can integrate intermittent renewables (e.g. solar and wind). Among the various technological options (e.g. lithium ion batteries, vanadium redox flow batteries), metal-air batteries are promising alternatives owing to their high energy density, safety, and use of abundant raw materials. Moreover, when combined with the principles of redox flow batteries, mass transfer is enhanced, which results in a more uniform metal deposition and a reduction in the metal electrode passivation [2]. Furthermore, metal-air flow batteries could enable decoupling of power and energy, while retaining the scalability advantages of redox flow batteries. Additionally, they are more compact than conventional redox flow batteries since only one electrolyte tank is needed. Several metal-air flow battery systems have been investigated such as vanadium-air [3], lithium-air [4] and zinc-air batteries [5]. However, they suffer from limitations which challenge their scalability. Specifically, vanadium is costly and only available in certain regions, lithium requires the use of organic solvents which compromises the battery safety, and zinc forms dendrites leading to a lower performance and safety issues. In this context, iron-based batteries are a promising alternative due to their high specific capacity, low cost, large availability, safety, non-toxicity, and recyclability. Compared to zinc, iron is also less prone to dendrite formation during cycling in aqueous electrolytes since iron deposition kinetics is slower[6]. Despite these advantages, the performance of the iron anode is limited by electrode degradation during cycling due to phase transformations, hydrogen evolution, and low utilization of the activate material [6], which motivates fundamental research to advance the performance and durability of the system. In this poster presentation, we will discuss the main goals of our new project FAIR-RFB [7]. Our overall aim is to develop a low cost and durable iron-air flow battery system and, to this goal, we will investigate, (i) the role of porous electrode microstructure in defining the performance of iron-air flow batteries, (ii) the influence of electrode surface properties in determining transport phenomena, kinetics, selectivity and durability, and (iii) new electrochemical reactor architectures for high power iron-air redox flow batteries. References: [1] O. Ruhnau and S. Qvist, Environ. Res. Lett., 17, 044018 (2022). [2] X. Han, X. Li, J. White, C. Zhong, Y. Deng, W. Hu and T. Ma, Adv. Energy Mater., 8, 1801396 (2018). [3] S. S. Hosseiny, M. Saakes and M. Wessling, Electrochem. Commun., 13, 751-754 (2011). [4] X. J. Chen, A. Shellikeri, Q. Wu, J. P. Zheng, M. Hendrickson and E. J. Plichta, J. Electrochem. Soc., 160, A1619 (2013). [5] M. Bockelmann, U. Kunz and T. Turek, Electrochem. Commun., 69, 24-27 (2016). [6] R. D. McKerracher, C. Ponce de Leon, R. G. A. Wills, A. A. Shah and F. C. Walsh, ChemPlusChem, 80, 323-335 (2015). [7] Horizon Europe. “Engineered Porous Electrodes to Unlock Ultra-low Cost Fe-Air Redox Flow Batteries”. European Commission. https://cordis.europa.eu/project/id/101042844.
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Tsutsumi, Jun’ya. "High-Throughput Nanoparticle Chemisorption Printing of Chemical Sensors with High-Wiring-Density Electrodes". Electronic Materials 2, n.º 2 (8 de abril de 2021): 72–81. http://dx.doi.org/10.3390/electronicmat2020007.
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We report on the high-throughput non-lithographic microprinting of a high-wiring-density interdigitated array electrode (line and space = 5 µm/5 µm), based on a facile wet/dewet patterning of silver nanoparticle ink. The trade-off between high-density wiring and pattern collapse in the wet/dewet patterning is overcome by employing a new herringbone design of interdigitated array electrode. We demonstrate electrochemical sensing of p-benzoquinone by the fabricated interdigitated array electrode, showing a typical steady-state I–V characteristics with superior signal amplification benefiting from the redox cycling effect. Our findings provide a new technical solution for the scalable manufacture of advanced chemical sensors, with an economy of scale that cannot be realized by other techniques.
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Díaz-Ramírez, Maryori, Víctor Ferreira, Tatiana García-Armingol, Ana López-Sabirón y Germán Ferreira. "Environmental Assessment of Electrochemical Energy Storage Device Manufacturing to Identify Drivers for Attaining Goals of Sustainable Materials 4.0". Sustainability 12, n.º 1 (1 de enero de 2020): 342. http://dx.doi.org/10.3390/su12010342.
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Electricity from the combination of photovoltaic panels and wind turbines exhibits potential benefits towards the sustainable cities transition. Nevertheless, the highly fluctuating and intermittent character limits an extended applicability in the energy market. Particularly, batteries represent a challenging approach to overcome the existing constraints and to achieve sustainable urban energy development. On the basis of the market roll-out and level of technological maturity, five commercially available battery technologies are assessed in this work, namely, lead–acid, lithium manganese oxide, nickel–cadmium, nickel–metal hydride, and vanadium redox flow. When considering sustainable development, environmental assessments provide valuable information. In this vein, an environmental analysis of the technologies is conducted using a life cycle assessment methodology from a cradle-to-gate perspective. A comparison of the environmental burden of battery components identified vanadium redox flow battery as the lowest environmental damage battery. In terms of components, electrodes; the electrolyte; and the set of pumps, motors, racks, and bolts exhibited the greatest environmental impact related to manufacturing. In terms of materials, copper, steel, sulphuric acid, and vanadium were identified as the main contributors to the midpoint impact categories. The results have highlighted that challenging materials 4.0 are still needed in battery manufacturing to provide sustainable technology designs required to the future urban planning based on circular economy demands.
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Hu, Xingyi. "Environmental and Health Impacts of Vanadium Redox Batteries: from Chemical Properties to Ecological Safety". Highlights in Science, Engineering and Technology 73 (29 de noviembre de 2023): 283–88. http://dx.doi.org/10.54097/hset.v73i.12988.
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Due to its distinct design and operation, the vanadium redox flow battery (VRFB) is a cutting-edge energy storage technology that has received a lot of attention lately. The active material of VRFB exists in liquid form, which brings many unique advantages to the battery. Unlike traditional solid-state batteries, the electrodes do not directly participate in chemical reactions during charging and discharging, thus significantly improving the service life of the battery. It is possible to change the VRFB's capacity without changing the battery itself. providing users with great flexibility. VRFB also has some other significant advantages, such as no toxicity by-products, environmental friendliness, high energy efficiency, and rapid response capability. In particular, for large-scale energy storage applications like grid peak shaving, Due to its excellent efficiency, VRFB has attracted a lot of interest. reliability, and economy. However, despite the aforementioned advantages of VRFB, it still faces some challenges in commercialization and large-scale application, such as cost, system complexity, and technology. Furthermore, this paper analyzes the security issues of VRFB in large-scale applications and aims to provide a comprehensive overview of the current state-of-the-art in VRB technology and its applications in various fields.
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Delgado, Dario. "A New Concept for the Electrosynthesis of Nanosized Nickel Oxyhydroxide Alloys for Alkaline Oxygen Evolution". Universal Journal of Electrochemistry 1, n.º 2 (21 de julio de 2023): 1. http://dx.doi.org/10.37256/ujec.1220232324.
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The objective of this concept article is to develop a new method for synthesizing nickel hydroxides, with a special interest in nickel oxyhydroxide (NiOx), which is extensively studied as an electrocatalyst for the alkaline oxygen evolution reaction (OER) in water electrolysis for hydrogen generation. The adoption of hydrogen economy faces several challenges, but effective OER catalysts can help to generate hydrogen cost-effectively for energy. We propose using the electrodeposition of NiOx from a redox surfactant microemulsion to create nanoscale NiOx particles that enhance the material’s electronic and geometric properties, leading to maximum energy efficiency for the OER. The microemulsion approach is a bottom-up technique that can be performed at low temperatures, making it a low-cost method. This technique can be used to synthesize other nanoscale materials.
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Anguebes-Franseschi, F., M. Abatal, Lucio Pat, A. Flores, A. V. Córdova Quiroz, M. A. Ramírez-Elias, L. San Pedro, O. May Tzuc y A. Bassam. "Raman Spectroscopy and Chemometric Modeling to Predict Physical-Chemical Honey Properties from Campeche, Mexico". Molecules 24, n.º 22 (13 de noviembre de 2019): 4091. http://dx.doi.org/10.3390/molecules24224091.
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In this work, 10 chemometric models based on Raman spectroscopy were constructed to predict the physicochemical properties of honey produced in the state of Campeche, Mexico. The properties of honey studied were pH, moisture, total soluble solids (TSS), free acidity, lactonic acidity, total acidity, electrical conductivity, Redox potential, hydroxymethylfurfural (HMF), and ash content. These proprieties were obtained according to the methods described by the Association of Official Analytical Chemists, Codex Alimentarius, and the International Honey Commission. For the construction of the chemometric models, 189 honey samples were collected and analyzed in triplicate using Raman spectroscopy to generate the matrix data [X], which were correlated with each of the physicochemical properties [Y]. The predictive capacity of each model was determined by cross validation and external validation, using the statistical parameters: standard error of calibration (SEC), standard error of prediction (SEP), coefficient of determination of cross-validation (R2cal), coefficient of determination for external validation (R2val), and Student’s t-test. The statistical results indicated that the chemometric models satisfactorily predict the humidity, TSS, free acidity, lactonic acidity, total acidity, and Redox potential. However, the models for electric conductivity and pH presented an acceptable prediction capacity but not adequate to supply the conventional processes, while the models for predicting ash content and HMF were not satisfactory. The developed models represent a low-cost tool to analyze the quality of honey, and contribute significantly to increasing the honey distribution and subsequently the economy of the region.
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Loureiro, Inês, Joana Faria, Nuno Santarem, Terry K. Smith, Joana Tavares y Anabela Cordeiro-da-Silva. "Potential Drug Targets in the Pentose Phosphate Pathway of Trypanosomatids". Current Medicinal Chemistry 25, n.º 39 (17 de enero de 2019): 5239–65. http://dx.doi.org/10.2174/0929867325666171206094752.
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The trypanosomatids, Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp, are causative agents of important human diseases such as African sleeping sickness, Chagas’ disease and Leishmaniasis, respectively. The high impact of these diseases on human health and economy worldwide, the unsatisfactory available chemotherapeutic options and the absence of human effective vaccines, strongly justifies the search for new drugs. The pentose phosphate pathway has been proposed to be a viable strategy to defeat several infectious diseases, including those from trypanosomatids, as it includes an oxidative branch, important in the maintenance of cell redox homeostasis, and a non-oxidative branch in which ribose 5-phosphate and erythrose 4-phosphate, precursors of nucleic acids and aromatic amino acids, are produced. This review provides an overview of the available chemotherapeutic options against these diseases and discusses the potential of genetically validated enzymes from the pentose phosphate pathway of trypanosomatids to be explored as potential drug targets.
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Díaz-Ramírez, Maryori C., Victor J. Ferreira, Tatiana García-Armingol, Ana M. López-Sabirón y Germán Ferreira. "Battery Manufacturing Resource Assessment to Minimise Component Production Environmental Impacts". Sustainability 12, n.º 17 (23 de agosto de 2020): 6840. http://dx.doi.org/10.3390/su12176840.
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A promising route to attain a reliable impact reduction of supply chain materials is based on considering circular economy approaches, such as material recycling strategies. This work aimed to evaluate potential benefits of recycling scenarios for steel, copper, aluminium and plastic materials to the battery manufacturing stage. Focused on this aim, the life cycle assessment (LCA) and the environmental externalities methodologies were applied to two battery study cases: lithium manganese oxide and vanadium redox flow (VRFB) batteries, based on a cradle-to-gate LCA approach. In general, the results provided an insight into the raw material handling route. Environmental impacts were diminished by more than 20% in almost all the indicators, due to the lower consumption of virgin materials related to the implemented recyclability route. Particularly, VRFB exhibited better recyclability ratio than the Li-ion battery. For the former, the key components were the periphery ones attaining around 70% of impact reduction by recycling steel. Components of the power subsystem were also relevant, reaching around 40% of environmental impact reduction by recycling plastic. The results also foresaw opportunities for membranes, key components of VRFB materials. Based on findings, recycling strategies may improve the total circularity performance and economic viability of the studied systems.
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van Maris, Antonius J. A., Aaron A. Winkler, Danilo Porro, Johannes P. van Dijken y Jack T. Pronk. "Homofermentative Lactate Production Cannot Sustain Anaerobic Growth of Engineered Saccharomyces cerevisiae: Possible Consequence of Energy-Dependent Lactate Export". Applied and Environmental Microbiology 70, n.º 5 (mayo de 2004): 2898–905. http://dx.doi.org/10.1128/aem.70.5.2898-2905.2004.
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ABSTRACT Due to a growing market for the biodegradable and renewable polymer polylactic acid, the world demand for lactic acid is rapidly increasing. The tolerance of yeasts to low pH can benefit the process economy of lactic acid production by minimizing the need for neutralizing agents. Saccharomyces cerevisiae (CEN.PK background) was engineered to a homofermentative lactate-producing yeast via deletion of the three genes encoding pyruvate decarboxylase and the introduction of a heterologous lactate dehydrogenase (EC 1.1.1.27). Like all pyruvate decarboxylase-negative S. cerevisiae strains, the engineered strain required small amounts of acetate for the synthesis of cytosolic acetyl-coenzyme A. Exposure of aerobic glucose-limited chemostat cultures to excess glucose resulted in the immediate appearance of lactate as the major fermentation product. Ethanol formation was absent. However, the engineered strain could not grow anaerobically, and lactate production was strongly stimulated by oxygen. In addition, under all conditions examined, lactate production by the engineered strain was slower than alcoholic fermentation by the wild type. Despite the equivalence of alcoholic fermentation and lactate fermentation with respect to redox balance and ATP generation, studies on oxygen-limited chemostat cultures showed that lactate production does not contribute to the ATP economy of the engineered yeast. This absence of net ATP production is probably due to a metabolic energy requirement (directly or indirectly in the form of ATP) for lactate export.
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Li, Wenzao, Mallory N. Vila, Lisa M. Housel, Nahian Sadique, Genesis D. Renderos, Steve Ehrlich, David C. Bock et al. "Operando bulk and interfacial characterization for electrochemical energy storage: Case study employing isothermal microcalorimetry and X-ray absorption spectroscopy". Journal of Materials Research 37, n.º 1 (25 de octubre de 2021): 319–33. http://dx.doi.org/10.1557/s43578-021-00350-y.
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Abstract The global shift to electricity as the main energy carrier will require innovation in electrochemical energy storage (EES). EES systems are the key to the “electron energy economy,” minimizing losses and increasing reliability between energy supply and demand. However, steep challenges such as cost, cycle/calendar life, energy density, material availability, and safety limit widespread adoption of batteries for large-scale grid and vehicle applications. Battery innovation that meets today’s challenges will require new chemistries, which can originate from understanding charge transport phenomena at multiple time and length scales. The advancement of operando characterization can expedite this progress as changes can be observed during battery function. This article highlights progress in bulk and interfacial operando characterization of batteries. Specifically, a case study involving Fe3O4 is provided demonstrating that combining X-ray absorption spectroscopy and isothermal microcalorimetry can provide real-time characterization of productive faradaic redox processes and parasitic interfacial reactions during (de)lithiation. Graphic abstract
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Roche, Stéphane P. "Recent Advances in Oxa-6π Electrocyclization Reactivity for the Synthesis of Privileged Natural Product Scaffolds". Organics 2, n.º 4 (26 de octubre de 2021): 376–87. http://dx.doi.org/10.3390/org2040021.
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The stunning advances in understanding the reactivity and selectivity principles of asymmetric pericyclic reactions have had a profound impact on the synthetic planning of complex natural products. Indeed, electrocyclizations, cycloadditions, and sigmatropic rearrangements enable synthetic chemists to craft highly functionalized scaffolds that would not otherwise be possible with a similar atom-, step-, and redox-economy. In this review, selected examples from the last two decades of research (2003–2020) on tandem processes combining oxa-6π electrocyclic reactions are discussed in terms of reactivity challenges, inherent reversibility, and key structural bond formation in the assembly of natural products. A particular emphasis is given to the electrocyclic ring-closures in the tandem processes featuring Knoevenagel-type condensations, Diels–Alder cycloadditions, Stille couplings, and oxidative dearomatizations. The synthetic manifolds reviewed here illustrate how oxa-6π electrocyclizations are intimately linked to the construction of complex natural product scaffolds and have inspired a number of biomimetic syntheses in the laboratory.
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Ding, Sujuan, Chao Hu, Jun Fang y Gang Liu. "The Protective Role of Probiotics against Colorectal Cancer". Oxidative Medicine and Cellular Longevity 2020 (9 de diciembre de 2020): 1–10. http://dx.doi.org/10.1155/2020/8884583.
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Colorectal cancer (CRC) is the fourth leading cause of cancer-related deaths worldwide and a major global public health problem. With the rapid development of the economy, the incidence of CRC has increased linearly. Accumulating evidence indicates that changes in the gut microenvironment, such as undesirable changes in the microbiota composition, provide favorable conditions for intestinal inflammation and shaping the tumor growth environment, whereas administration of certain probiotics can reverse this situation to a certain extent. This review summarizes the roles of probiotics in the regulation of CRC, such as enhancing the immune barrier, regulating the intestinal immune state, inhibiting pathogenic enzyme activity, regulating CRC cell proliferation and apoptosis, regulating redox homeostasis, and reprograming intestinal microbial composition. Abundant studies have provided a theoretical foundation for the roles of probiotics in CRC prevention and treatment, but their mechanisms of action remain to be investigated, and further clinical trials are warranted for the application of probiotics in the target population.
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Gucciardi, Emanuele, Montserrat Galceran, Ainhoa Bustinza, Emilie Bekaert y Montserrat Casas-Cabanas. "Circular Economy Insights: Sustainable Reuse of Aged Li-Ion LiFePO4 Cathodes within Na-Ion Cells". ECS Meeting Abstracts MA2022-01, n.º 5 (7 de julio de 2022): 595. http://dx.doi.org/10.1149/ma2022-015595mtgabs.
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Lithium-ion batteries (LIBs) are today considered as one of the best solutions towards an energy model based on renewable sources and zero-emission electric vehicles. However, the increased production of LIBs raises concerns regarding cost and availability of key materials such as lithium, cobalt or graphite. Indeed, after almost 20 years of cost decrease, the price of lithium-ion batteries is slowing down [1]. This is related to the fact that a lot of raw materials and metals (mainly copper, aluminum and cobalt) that are used in LiBs have increased relentlessly their prices because of its continuous demand. In this sense, are needed better performing, more price competitive and sustainable battery storage solutions beyond lithium that take into consideration the overall value chain, from access to raw material, innovative advanced materials, production, recycling and second life. In this context, disposal and recycling are essential for the sustainability of this market and new recycling processes for LIBs are needed. Today there are processes that can recover high-value raw materials from LIBs (mainly copper, aluminum, and cobalt) but direct recycling of materials such as LiFePO4 (LFP) that has less economic value and are environmentally much more sustainable represents an economic challenge for the battery market and future research. NaFePO4 (NFP) has been indeed proposed as one of the cheapest and most sustainable sodium-ion (Na-ion) cathode materials, [2-3] but it is not a thermodynamically stable phase and it is necessary to obtain it from LFP through redox reactions usually using expensive, toxic and hazardous reagents, cutting down its commercialization.[3-5] LFP recovering from spent LIBs can contribute to reducing the manufacturing costs of the NFP and increase the interest to recycle Li-ion batteries based on LFP cathodes. In the perspective of a circular economy market, we propose in this work to explore the recovery of aged LFP electrodes and their reuse in new Na-ion batteries.
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Cabecas Segura, Paloma, Quentin De Meur, Audrey Tanghe, Rob Onderwater, Laurent Dewasme, Ruddy Wattiez y Baptiste Leroy. "Effects of Mixing Volatile Fatty Acids as Carbon Sources on Rhodospirillum rubrum Carbon Metabolism and Redox Balance Mechanisms". Microorganisms 9, n.º 9 (21 de septiembre de 2021): 1996. http://dx.doi.org/10.3390/microorganisms9091996.
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Rhodospirillum rubrum has a versatile metabolism, and as such can assimilate a broad range of carbon sources, including volatile fatty acids. These carbon sources are gaining increasing interest for biotechnological processes, since they reduce the production costs for numerous value-added compounds and contribute to the development of a more circular economy. Usually, studies characterizing carbon metabolism are performed by supplying a single carbon source; however, in both environmental and engineered conditions, cells would rather grow on mixtures of volatile fatty acids (VFAs) generated via anaerobic fermentation. In this study, we show that the use of a mixture of VFAs as carbon source appears to have a synergy effect on growth phenotype. In addition, while propionate and butyrate assimilation in Rs. rubrum is known to require an excess of bicarbonate in the culture medium, mixing them reduces the requirement for bicarbonate supplementation. The fixation of CO2 is one of the main electron sinks in purple bacteria; therefore, this observation suggests an adaptation of both metabolic pathways used for the assimilation of these VFAs and redox homeostasis mechanism. Based on proteomic data, modification of the propionate assimilation pathway seems to occur with a switch from a methylmalonyl-CoA intermediate to the methylcitrate cycle. Moreover, it seems that the presence of a mixture of VFAs switches electron sinking from CO2 fixation to H2 and isoleucine production.
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Suss, Matthew, Shada Abu Khalla, Arunchander Asokan y Salman Abdalla. "Simultaneous Generation of Clean Water and Electricity Via Desalination Fuel Cells". ECS Meeting Abstracts MA2022-02, n.º 40 (9 de octubre de 2022): 1461. http://dx.doi.org/10.1149/ma2022-02401461mtgabs.
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We will present a nascent technology which desalinates water and produces net electricity simultaneously from a single electrochemical cell, driven by the hydrogen/oxygen redox couple [1]. The cell combines hardware of PEM fuel cells, alkaline fuel cells and electrodialysis cells, and thus we term this device a "desalination fuel cell" [2]. We will describe both the operating principle and lab-scale cell results, as well as our development of the fundamental thermodynamics to predict the maximum available electricity production from our cell during its combined chemical reaction-separation process [2]. Our recent advances will be described, including the development of chloride-tolerant non-platinum group metal ORR catalysts [3], achievement of >95% thermodynamic energy efficiency [4], and establishment of system scaling rules. This technology promises to extend the concept of the hydrogen economy to water purification, and we will discuss the outlook on this technology and potential application areas. References: [1] Suss ME, Zhang Y, Atlas I, Gendel Y, Ruck EB, Presser V. Emerging, hydrogen-driven electrochemical water purification. Electrochemistry Communications. 2022 [2] Atlas I, Khalla SA, Suss ME. Thermodynamic energy efficiency of electrochemical systems performing simultaneous water desalination and electricity generation. Journal of The Electrochemical Society. 2020. [3] Asokan A, Abu-Khalla S, Abdalla S, Suss ME. Chloride-Tolerant, Inexpensive Fe/N/C Catalysts for Desalination Fuel Cell Cathodes. ACS Applied Energy Materials. 2022. [4] Abu Khalla S, Atlas I, Litster S, Suss ME. Desalination Fuel Cells with High Thermodynamic Energy Efficiency. Environmental science & technology. 2021. Figure 1: Schematic of a desalination fuel cell, which utilizes chemical energy to desalinate water and produce electricity simultaneously. The cell is driven by the hydrogen-oxygen redox couple. Figure 1
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Chen, Haoming, Tianle Li, Zhiming Xu, Wenju Wang y Haihou Wang. "Oxidation of soot promoted by Fe-based spinel catalysts". Materials Research Express 9, n.º 1 (1 de enero de 2022): 015502. http://dx.doi.org/10.1088/2053-1591/ac3f5d.
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Abstract Diesel engine has attracted much attention because of its good power performance, fuel economy, reliability and durability, but the exhaust gas containing soot has significant impact on environment and human health. Catalyzed diesel particulate filter (CDPF) that reduces the activation energy of soot oxidation by catalysts are used to eliminate soot. In this work, MFe2O4 spinel (M = Cu, Ni and Co) was synthesized by sol-gel method to catalyze the oxidation of soot. The characterization results of MFe2O4 showed that CuFe2O4 possessed the smallest average grain size (65.6 nm) and the best redox performance. The activity tests of the catalysts showed that the activity order of the catalyst is CuFe2O4 (330 °C > CoFe2O4 (411 °C > NiFe2O4 (464 °C. DFT results showed that soot is more easily adsorbed on the O-terminal surface of CuFe2O4 and reacts with oxygen vacancies, resulting in the promotion of soot oxidation by the diffusion of oxygen from the inside to the surface. It also proves that CuFe2O4 has the best catalytic effect on soot.
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Moisieieva, N. V., A. A. Kapustianska y O. H. Shumeiko. "GONADOPROTECTIVE PROPERTIES OF ANTIOXIDANT COMPLEX IN CONDITIONS CAUSED BY TOXIC EFFECTS OF HERBICIDES". Актуальні проблеми сучасної медицини: Вісник Української медичної стоматологічної академії 20, n.º 1 (9 de abril de 2020): 36–39. http://dx.doi.org/10.31718/2077-1096.20.1.36.
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Nowadays, when the nation’s temporary economic difficulties have led to a decline in the agriculture share of the overall economy, the problem of controlling weeds of agricultural land is especially urgent. Undoubtedly, in our country, with the strengthening of the economy, the use of plant protection products is growing, requiring even closer attention to the problem of the environmental impact of herbicides and the rehabilitation of soils contaminated with residues of poisonous chemicals. The general mechanism of the action affecting herbicides of different groups is the violation of redox processes, and, in particular, the increase in free radical lipid peroxidation, first of all, in gonadal cell membranes that can eventually lead to the destruction throughout the reproductive period. Moreover, they produce gonadotoxic effects leading to a decrease in steroidogenesis, and as a consequence, to impaired spermatogenesis.
The aim of the study was to investigate the gonadoprotective properties of the antioxidant complex, its effect on the parameters of lipid peroxidation, morphological and functional changes in the testes of rats exposed to the toxic effect of the clopyralid herbicide.
The introduction of this complex under the conditions mentioned above contributed not only to a significant decrease in free radical lipid perozidation in the blood and tissues of the testes, but also to normalization of the state of spermatogenic epithelium, quantitative sperm indicators, normalization of sperm motility. It has been proven the complex of antioxidants not only affects the level of spermatogenic epithelium, but also improves the quality of sperm, contributing to the restoration of sperm motility. The studies of morphological changes in the testes and the functional maturation of the sperm have shown that the most significant changes were registered during the correction with the antioxidant complex, emphasizing its more pronounced gonadoprotective effect.
The results obtained indicate the feasibility of using this antioxidant complex as gonadoprotectant in cases of chronic intoxication with herbicides.
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Xu, Quan, Xinyi Chen, Siyang Wang, Chao Guo, Yingchun Niu, Runguo Zuo, Ziji Yang, Yang Zhou y Chunming Xu. "The Recycling of Waste Per-Fluorinated Sulfonic Acid for Reformulation and Membrane Application in Iron-Chromium Redox Flow Batteries". Energies 15, n.º 22 (20 de noviembre de 2022): 8717. http://dx.doi.org/10.3390/en15228717.
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Iron–chromium redox flow batteries (ICRFB) possess the advantage of low raw material cost, intrinsic safety, long charge–discharge cycle life, good life-cycle economy, and environmental friendliness, which has attracted attention from academia and industry over time. The proton exchange membrane (PEM) is an important part of the ICRFB system, impacting the efficiency and lifetime of the battery. Currently, the most widely used PEMs in the market are per-fluorinated sulfonic acid (PFSA) membranes, which possess high electrolyte stability and achieve the separation of positive and negative electrolytes. In addition, the complex preparation process and extremely high market price limited the usage of PEM in ICRFB. In this paper, we developed a remanufactured membrane (RM) strategy from waste PFSA resins. The RM has higher electrical conductivity and better proton transport ability than the commodity membrane N212. In the cell performance test, the RM exhibits similar coulombic efficiency (CE) as N212 at different current densities, which is stabilized at over 95%. Furthermore, the voltage efficiency (VE) and energy efficiency (EE) of the RM are improved compared to N212. At a current strength of 140 mA cm−2, the degree of energy loss is lower in the RM, and after 60 cycles, the capacity decay rate is lower by only 16.66%, leading to long-term battery life. It is a cost-effective method for membrane recovery and reformulation, which is suitable for large-scale application of ICRFB in the future.
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Mairet, Francis. "A biomolecular proportional integral controller based on feedback regulations of protein level and activity". Royal Society Open Science 5, n.º 2 (febrero de 2018): 171966. http://dx.doi.org/10.1098/rsos.171966.
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Homeostasis is the capacity of living organisms to keep internal conditions regulated at a constant level, despite environmental fluctuations. Integral feedback control is known to play a key role in this behaviour. Here, I show that a feedback system involving transcriptional and post-translational regulations of the same executor protein acts as a proportional integral (PI) controller, leading to enhanced transient performances in comparison with a classical integral loop. Such a biomolecular controller—which I call a level and activity-PI controller (LA-PI)—is involved in the regulation of ammonium uptake by Escherichia coli through the transporter AmtB. The P II molecules, which reflect the nitrogen status of the cell, inhibit both the production of AmtB and its activity (via the NtrB-NtrC system and the formation of a complex with GlnK, respectively). Other examples of LA-PI controller include copper and zinc transporters, and the redox regulation in photosynthesis. This scheme has thus emerged through evolution in many biological systems, surely because of the benefits it offers in terms of performances (rapid and perfect adaptation) and economy (protein production according to needs).
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Saeedi, Soroosh, Xuan Trung Nguyen, Filippo Bossola, Claudio Evangelisti y Vladimiro Dal Dal Santo. "Methane Reforming Processes: Advances on Mono- and Bimetallic Ni-Based Catalysts Supported on Mg-Al Mixed Oxides". Catalysts 13, n.º 2 (9 de febrero de 2023): 379. http://dx.doi.org/10.3390/catal13020379.
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Ni-based catalysts supported on Mg-Al mixed oxides (Mg(Al)O) have been intensively investigated as catalysts for CH4 reforming processes (i.e., steam reforming (SMR) and dry reforming (DRM)), which are pivotal actors in the expanding H2 economy. In this review, we provide for the first time an in-depth analysis of homo- and bimetallic Ni-based catalysts supported on Mg(Al)O supports reported to date in the literature and used for SMR and DRM processes. Particular attention is devoted to the role of the synthesis protocols on the structural and morphological properties of the final catalytic materials, which are directly related to their catalytic performance. It turns out that the addition of a small amount of a second metal to Ni (bimetallic catalysts), in some cases, is the most practicable way to improve the catalyst durability. In addition, besides more conventional approaches (i.e., impregnation and co-precipitation), other innovative synthesis methods (e.g., sol-gel, atomic layer deposition, redox reactions) and pretreatments (e.g., plasma-based treatments) have shown relevant improvements in identifying and controlling the interaction among the constituents most useful to improve the overall H2 productivity.
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Dolzhenko, Lidia, Natalia Yudina y Elena Shchutskaya. "Biopositive water environment as a basis for sustainable development of urban areas". E3S Web of Conferences 371 (2023): 06024. http://dx.doi.org/10.1051/e3sconf/202337106024.
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The development of a large city regions has a noticeable dependence of a local ecological situation. To motivate their stable growth and to create human-friendly environment the technologies of nature regeneration is needed. One of the approaches available is the implementation of hinged water modular systems containing a filtering higher plants. Among the practical consequences of this method – the prevention of water flowering that is especially useful for in-city reservoirs. The paper presented is devoted to investigation of a stepped mesh structure of this type that holds a plantings of water hyacinth. The macromorphological characteristics of the colonies attached to the assessment of nitrogen-transforming biocenosis according to the total index of species diversity were studied. The results show that the redox capacity reserves of phytostructure biomodules are more than 40% while the nitrification efficiency is about 90%. In addition to plant adsorption effect the increased formation of activated sludge takes place. The concept allows to start an effective exploitation immediately after the placement and leads to significant financial economy after the first year of using. In general, the approach presented is easily adaptable and can be used for most of the existing in-city water reservoirs.
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Jacquemond, Remy Richard, Maxime van der Heijden, Emre Burak Boz, E. Ricardo Carreon-Ruiz, Vanesa Muñoz Perales, Kitty Nijmeijer, Pierre Boillat y Antoni Forner-Cuenca. "Investigating Transport through Membranes in Non-Aqueous Redox Flow Batteries with Neutron Radiography". ECS Meeting Abstracts MA2023-01, n.º 47 (28 de agosto de 2023): 2514. http://dx.doi.org/10.1149/ma2023-01472514mtgabs.
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Electrochemical technologies offer a strong platform to decarbonize and electrify our energy economy and thus are poised to play an increasingly important role. Nevertheless, all electrochemical technologies suffer from thermodynamic, kinetic, and other operational losses that can drastically limit the performance of the device. Current macroscopic characterization techniques used to assess those losses (i.e., polarization, electrochemical impedance spectroscopy) fail to assess local inefficiencies challenging complete understanding of the system being investigated. Operando imaging of electrochemical systems, in tandem with electrochemical diagnostics offers a viable option to resolve local information and correlate it with macroscopic electrochemical performance. This dual characterization strategy has been successfully applied for the development of other electrochemical technologies (i.e., polymer electrolyte fuel cells[1,2], lithium-ion batteries[3,4]). In the past years, several groups developed and investigated imaging and spectroscopic techniques for operando characterization of redox flow batteries (RFBs) such as fluorescence microscopy[5], nuclear magnetic resonance spectroscopy[6,7] and infrared thermography[8]. Only recently, Clement et al. reported for the first time the use of neutron radiography to perform through-plane imaging of the gas evolution during operation of an all-vanadium RFB[9]. However, an approach enabling non-invasive operando concentration mapping of the species of interest within the reactor area has remained elusive. In this work, we develop two novel neutron radiography operando methodologies to quantify concentration distributions in RFBs. We first perform cuvette experiments to calibrate the neutron attenuation response of the redox active materials (i.e., TEMPO and TEMPO+) and supporting salts (i.e., BF4 -) used in this study. We find a linear response between the neutron absorption and the concentrations of the species of interest in the electrolyte in the studied range (0.0 to 0.5 M). Next, we performed experiments with redox flow cells under operation and use the ex-situ calibrations together with subtractive neutron imaging to quantify species concentration in the electrolyte. By employing an in-plane optical imaging setup[10], we can resolve species concentration across the porous electrodes (Figure 1). We observe strong variations in the concentration profiles within the reactor area upon changes in the operating conditions and link those differences to material properties (i.e., membrane electrostatic charge). Finally, I will discuss our latest results obtained using time-of-flight neutron imaging to deconvolute concentration maps for TEMPO/TEMPO+ and BF4 - species. Using this methodology, we study mass transport across a porous separator and a dense anion exchange membrane. We find that, while TEMPO/TEMPO+ and BF4 - show almost symmetrical concentration changes in the case of a porous separator, asymmetric transport occurs when a charge selective membrane is used where only BF4 - is allowed to crossover the anion exchange polymer. The developed methodology offers a non-invasive diagnostic tool to image concentration distributions in electrochemical cells and can be applied to support theoretical and experimental efforts aiming to understand the role of materials and reactor designs on complex mass transport phenomena. [1] P. Boillat, E. H. Lehmann, P. Trtik, M. Cochet, Current Opinion in Electrochemistry 2017, 5, 3. [2] J. Eller, T. Rosén, F. Marone, M. Stampanoni, A. Wokaun, F. N. Büchi, J. Electrochem. Soc. 2011, 158, B963. [3] B. Michalak, H. Sommer, D. Mannes, A. Kaestner, T. Brezesinski, J. Janek, Sci Rep 2015, 5, 15627. [4] D. P. Finegan, M. Scheel, J. B. Robinson, B. Tjaden, I. Hunt, T. J. Mason, J. Millichamp, M. Di Michiel, G. J. Offer, G. Hinds, D. J. L. Brett, P. R. Shearing, Nat Commun 2015, 6, 6924. [5] A. A. Wong, M. J. Aziz, S. Rubinstein, ECS Trans. 2017, 77, 153. [6] E. W. Zhao, T. Liu, E. Jónsson, J. Lee, I. Temprano, R. B. Jethwa, A. Wang, H. Smith, J. Carretero-González, Q. Song, C. P. Grey, Nature 2020, 579, 224. [7] E. W. Zhao, E. Jónsson, R. B. Jethwa, D. Hey, D. Lyu, A. Brookfield, P. A. A. Klusener, D. Collison, C. P. Grey, J. Am. Chem. Soc. 2021, 143, 1885. [8] H. Tanaka, Y. Miyafuji, J. Fukushima, T. Tayama, T. Sugita, M. Takezawa, T. Muta, Journal of Energy Storage 2018, 19, 67. [9] J. T. Clement, Investigation of Localized Performance and Gas Evolution in All-Vanadium Redox Flow Batteries via in-Situ Distributed Diagnostic Techniques, Ph.D. thesis, University of Tennessee, 2016. [10] P. Boillat, G. Frei, E. H. Lehmann, G. G. Scherer, A. Wokaun, Electrochem. Solid-State Lett. 2010, 13, B25. Figure 1
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Pethaiah, Sethu Sundar, Kishor Kumar Sadasivuni, Arunkumar Jayakumar, Deepalekshmi Ponnamma, Chandra Sekhar Tiwary y Gangadharan Sasikumar. "Methanol Electrolysis for Hydrogen Production Using Polymer Electrolyte Membrane: A Mini-Review". Energies 13, n.º 22 (11 de noviembre de 2020): 5879. http://dx.doi.org/10.3390/en13225879.
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Hydrogen (H2) has attained significant benefits as an energy carrier due to its gross calorific value (GCV) and inherently clean operation. Thus, hydrogen as a fuel can lead to global sustainability. Conventional H2 production is predominantly through fossil fuels, and electrolysis is now identified to be most promising for H2 generation. This review describes the recent state of the art and challenges on ultra-pure H2 production through methanol electrolysis that incorporate polymer electrolyte membrane (PEM). It also discusses about the methanol electrochemical reforming catalysts as well as the impact of this process via PEM. The efficiency of H2 production depends on the different components of the PEM fuel cells, which are bipolar plates, current collector, and membrane electrode assembly. The efficiency also changes with the nature and type of the fuel, fuel/oxygen ratio, pressure, temperature, humidity, cell potential, and interfacial electronic level interaction between the redox levels of electrolyte and band gap edges of the semiconductor membranes. Diverse operating conditions such as concentration of methanol, cell temperature, catalyst loading, membrane thickness, and cell voltage that affect the performance are critically addressed. Comparison of various methanol electrolyzer systems are performed to validate the significance of methanol economy to match the future sustainable energy demands.
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Lima, Leonardo Warzea, Serenella Nardi, Veronica Santoro y Michela Schiavon. "The Relevance of Plant-Derived Se Compounds to Human Health in the SARS-CoV-2 (COVID-19) Pandemic Era". Antioxidants 10, n.º 7 (25 de junio de 2021): 1031. http://dx.doi.org/10.3390/antiox10071031.
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Dietary selenium (Se)-compounds accumulated in plants are essential for human metabolism and normal physiological processes. Inorganic and organic Se species can be readily absorbed by the human body, but are metabolized differently and thus exhibit distinct mechanisms of action. They can act as antioxidants or serve as a source of Se for the synthesis of selenoproteins. Selenocysteine, in particular, is incorporated at the catalytic center of these proteins through a specific insertion mechanism and, due to its electronic features, enhances their catalytic activity against biological oxidants. Selenite and other Se-organic compounds may also act as direct antioxidants in cells due to their strong nucleophilic properties. In addition, Se-amino acids are more easily subjected to oxidation than the corresponding thiols/thioethers and can bind redox-active metal ions. Adequate Se intake aids in preventing several metabolic disorders and affords protection against viral infections. At present, an epidemic caused by a novel coronavirus (SARS-CoV-2) threatens human health across several countries and impacts the global economy. Therefore, Se-supplementation could be a complementary treatment to vaccines and pharmacological drugs to reduce the viral load, mutation frequency, and enhance the immune system of populations with low Se intake in the diet.
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Mahamat Ahmat, Adoum y Yannick Mamindy-Pajany. "Over-sulfated soils and sediments treatment: A brief discussion on performance disparities of biological and non-biological methods throughout the literature". Waste Management & Research: The Journal for a Sustainable Circular Economy 39, n.º 4 (18 de enero de 2021): 528–45. http://dx.doi.org/10.1177/0734242x20982053.
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High sulfate concentrations in industrial effluents as well as solid materials (excavated soils, dredged sediments, etc.) are a major hindrance for circular economy outlooks. SO42- acceptability standards are indeed increasingly restrictive, given the potential outcomes for public health and ecosystems. This literature review deals with the treatment pathways relying on precipitation, adsorption and microbial redox principles. Although satisfactory removal performances can be achieved with each of them, significant yield differences are displayed throughout the bibliography. The challenge here was to identify the parameters leading to this variability and to assess their impact. The precipitation pathway is based on the formation of two main minerals (ettringite and barite). It can lead to total sulfate removal but can also be limited by aqueous wastes chemistry. Stabilizer kinetics of formation and equilibrium are highly constrained by background properties such as pH, Eh, SO42- saturation state and inhibiting metal occurrences. Regarding the adsorption route, sorbents’ intrinsic features such as the qmax parameter govern removal yields. Concerning the microbial pathway, the chemical oxygen demand/SO42- ratio and the hydraulic retention time, which are classically evoked as yield variation factors, appear here to be weakly influential. The effect of these parameters seems to be overridden by the influence of electron donors, which constitute a first order factor of variability. A second order variability can be read according to the nature of these electron donors. Approaches using simple monomers (ethanol lactates, etc.) perform better than those using predominantly ligneous organic matter.
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Schink, B. "Energetics of syntrophic cooperation in methanogenic degradation". Microbiology and Molecular Biology Reviews 61, n.º 2 (junio de 1997): 262–80. http://dx.doi.org/10.1128/mmbr.61.2.262-280.1997.
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Fatty acids and alcohols are key intermediates in the methanogenic degradation of organic matter, e.g., in anaerobic sewage sludge digestors or freshwater lake sediments. They are produced by classical fermenting bacteria for disposal of electrons derived in simultaneous substrate oxidations. Methanogenic bacteria can degrade primarily only one-carbon compounds. Therefore, acetate, propionate, ethanol, and their higher homologs have to be fermented further to one-carbon compounds. These fermentations are called secondary or syntrophic fermentations. They are endergonic processes under standard conditions and depend on intimate coupling with methanogenesis. The energetic situation of the prokaryotes cooperating in these processes is problematic: the free energy available in the reactions for total conversion of substrate to methane attributes to each partner amounts of energy in the range of the minimum biochemically convertible energy, i.e., 20 to 25 kJ per mol per reaction. This amount corresponds to one-third of an ATP unit and is equivalent to the energy required for a monovalent ion to cross the charged cytoplasmic membrane. Recent studies have revealed that syntrophically fermenting bacteria synthesize ATP by substrate-level phosphorylation and reinvest part of the ATP-bound energy into reversed electron transport processes, to release the electrons at a redox level accessible by the partner bacteria and to balance their energy budget. These findings allow us to understand the energy economy of these bacteria on the basis of concepts derived from the bioenergetics of other microorganisms.
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Dang, Hoang, Andrew J. Sellathurai y Dominik PJ Barz. "An Ion Exchange Membrane-Free, Ultrastable Zinc-Iodine Battery Enabled by Functionalized Graphene Electrodes". ECS Meeting Abstracts MA2023-01, n.º 5 (28 de agosto de 2023): 908. http://dx.doi.org/10.1149/ma2023-015908mtgabs.
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Global warming requires a shift in the energy economy towards renewable energy sources, such as solar and wind energy, to meet the ever-increasing worldwide energy demand while having lesser negative impact on the environment. The integration of such sustainable energy resources into the existing infrastructure, however, is challenging due to their fluctuations and intermittences requiring the development of efficient (intermediate) energy storage systems. The ultimate goal for these systems pertains to high performance, durability, safety, facile scalability, cost, and environmental-friendliness. The aqueous rechargeable zinc-iodine (Zn-I2) battery is promising due to the high theoretical capacities of Zn (820 mAh gZn -1) and I2 (211 mA h gI2 -1) along with the very high solubilities in aqueous media. Other advantages include the abundance of the electrode materials and the safety of the aqueous electrolyte. The high energy density of aqueous zinc-based batteries is a result of the multi-electron redox reactions and the low electrochemical potential of Zn (-0.763 V vs. RHE) in mildly acidic electrolytes such as in a Zn-I2 battery. In addition, compared to other alkali metals such as lithium, sodium, and potassium, metallic Zn is relatively stable in an aqueous environment over a wide temperature range. Several challenges need to be addressed for Zn-I2 batteries to be competitive; namely, self-discharge, sluggish kinetics, low practical energy density, as well as the dendrite formation on the Zn anode. In this work, we design a high-performance Zn-I2 battery with an unusual long-term stability which is based on a novel design of electrodes and electrolyte. In detail, a three-dimensional functionalized graphene cathode facilitates the iodide redox reactions and also immobilizes dissolved polyiodides; thus, suppressing the detrimental shuttling effect. Furthermore, we design a composite anode made of Zn coated with a film of reduced graphene oxide. This modification significantly enhances the performance and stabilizes the anode during repeated Zn stripping/plating preventing dendrite formation. The electrolyte is formulated in a way that, along with the graphene-based cathode, allows for the utilization of an economical glass fiber separator instead of the commonly employed ion-exchange membranes, which are expensive and have relatively high ohmic resistances. Our novel Zn-I2 battery design exhibit high current efficiencies of nearly 100%, along with stable specific capacities of 257, 186, 150, 84 mAh g-1 at corresponding current densities of 1, 2, 5, 10 A g-1. Furthermore, a long-term capacity retention of 96.7% at 5 A g-1 over 2000 cycles is achieved, outperforming most comparable aqueous batteries.