Journal articles: 'Transition Metal Oxides (TMOs)'

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Mitchell, James B., Matthew Chagnot, and Veronica Augustyn. "Hydrous Transition Metal Oxides for Electrochemical Energy and Environmental Applications." Annual Review of Materials Research 53, no. 1 (July 3, 2023): 1–23. http://dx.doi.org/10.1146/annurev-matsci-080819-124955.

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Hydrous transition metal oxides (TMOs) are redox-active materials that confine structural water within their bulk, organized in 1D, 2D, or 3D networks. In an electrochemical cell, hydrous TMOs can interact with electrolyte species not only via their outer surface but also via their hydrous inner surface, which can transport electrolyte species to the interior of the material. Many TMOs operating in an aqueous electrochemical environment transform to hydrous TMOs, which then serve as the electrochemically active phase. This review summarizes the physicochemical properties of hydrous TMOs and recent mechanistic insights into their behavior in electrochemical reactions of interest for energy storage, conversion, and environmental applications. Particular focus is placed on first-principles calculations and operando characterization to obtain an atomistic view of their electrochemical mechanisms. Hydrous TMOs represent an important class of energy and environmental materials in aqueous and nonaqueous environments. Further understanding of their interaction with electrolyte species is likely to yield advancements in electrochemical reactivity and kinetics for energy and environmental applications.

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Chen, Da, Quan Ming Li, and Wang Gao. "Role of van der Waals forces in the metal–insulator transition of transition metal oxides." Physical Chemistry Chemical Physics 24, no. 9 (2022): 5455–61. http://dx.doi.org/10.1039/d2cp00282e.

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Bishop, Alan R. "A Lattice Litany for Transition Metal Oxides." Condensed Matter 5, no. 3 (July 13, 2020): 46. http://dx.doi.org/10.3390/condmat5030046.

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In this tribute to K Alex Müller, I describe how his early insights have influenced future decades of research on perovskite ferroelectrics and more broadly transition metal oxides (TMOs) and related quantum materials. I use his influence on my own research journey to discuss impacts in three areas: structural phase transitions, precursor structure, and quantum paraelectricity. I emphasize materials functionality in ground, metastable, and excited states arising from competitions among lattice, charge, and spin degrees of freedom, which results in highly tunable landscapes and complex networks of multiscale configurations controlling macroscopic functions. I discuss competitions between short- and long-range forces as particularly important in TMOs (and related materials classes) because of their localized and directional metal orbitals and the polarizable oxygen ions. I emphasize crucial consequences of elasticity and metal–oxygen charge transfer.

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Prajapati, Aditya, Brianna A. Collins, Jason D. Goodpaster, and Meenesh R. Singh. "Fundamental insight into electrochemical oxidation of methane towards methanol on transition metal oxides." Proceedings of the National Academy of Sciences 118, no. 8 (February 17, 2021): e2023233118. http://dx.doi.org/10.1073/pnas.2023233118.

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Electrochemical oxidation of CH4 is known to be inefficient in aqueous electrolytes. The lower activity of methane oxidation reaction (MOR) is primarily attributed to the dominant oxygen evolution reaction (OER) and the higher barrier for CH4 activation on transition metal oxides (TMOs). However, a satisfactory explanation for the origins of such lower activity of MOR on TMOs, along with the enabling strategies to partially oxidize CH4 to CH3OH, have not been developed yet. We report here the activation of CH4 is governed by a previously unrecognized consequence of electrostatic (or Madelung) potential of metal atom in TMOs. The measured binding energies of CH4 on 12 different TMOs scale linearly with the Madelung potentials of the metal in the TMOs. The MOR active TMOs are the ones with higher CH4 binding energy and lower Madelung potential. Out of 12 TMOs studied here, only TiO2, IrO2, PbO2, and PtO2 are active for MOR, where the stable active site is the O on top of the metal in TMOs. The reaction pathway for MOR proceeds primarily through *CHx intermediates at lower potentials and through *CH3OH intermediates at higher potentials. The key MOR intermediate *CH3OH is identified on TiO2 under operando conditions at higher potential using transient open-circuit potential measurement. To minimize the overoxidation of *CH3OH, a bimetallic Cu2O3 on TiO2 catalysts is developed, in which Cu reduces the barrier for the reaction of *CH3 and *OH and facilitates the desorption of *CH3OH. The highest faradaic efficiency of 6% is obtained using Cu-Ti bimetallic TMO.

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Liu, Wei, Qun Xu, and Yannan Zhou. "CO2-assisted fabrication of two-dimensional amorphous transition metal oxides." Dalton Transactions 49, no. 7 (2020): 2048–52. http://dx.doi.org/10.1039/c9dt04651h.

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Wu, Zhuo-Dong, De-Jian Chen, Long Li, and Li-Na Wang. "A universal electrochemical lithiation–delithiation method to prepare low-crystalline metal oxides for high-performance hybrid supercapacitors." RSC Advances 11, no. 48 (2021): 30407–14. http://dx.doi.org/10.1039/d1ra05814b.

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Rong, Kai, Jiale Wei, Liang Huang, Youxing Fang, and Shaojun Dong. "Synthesis of low dimensional hierarchical transition metal oxides via a direct deep eutectic solvent calcining method for enhanced oxygen evolution catalysis." Nanoscale 12, no. 40 (2020): 20719–25. http://dx.doi.org/10.1039/d0nr04378h.

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Wu, Jian, Wen-Jin Yin, Wei-Wei Liu, Pan Guo, Guobiao Liu, Xicuan Liu, Dongsheng Geng, Woon-Ming Lau, Hao Liu, and Li-Min Liu. "High performance NiO nanosheets anchored on three-dimensional nitrogen-doped carbon nanotubes as a binder-free anode for lithium ion batteries." Journal of Materials Chemistry A 4, no. 28 (2016): 10940–47. http://dx.doi.org/10.1039/c6ta03137d.

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Zhou, Chuan, Haiyang Yuan, P. Hu, and Haifeng Wang. "A general doping rule: rational design of Ir-doped catalysts for the oxygen evolution reaction." Chemical Communications 56, no. 96 (2020): 15201–4. http://dx.doi.org/10.1039/d0cc06282k.

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Zhao, Zijian, Guiying Tian, Angelina Sarapulova, Lihua Zhu, and Sonia Dsoke. "Influence of phase variation of ZnMn2O4/carbon electrodes on cycling performances of Li-ion batteries." Inorganic Chemistry Frontiers 7, no. 19 (2020): 3657–66. http://dx.doi.org/10.1039/d0qi00610f.

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Sachs, Michael, Liam Harnett-Caulfield, Ernest Pastor, Jenny Nelson, Aron Walsh, and James Durrant. "(Invited) Ultrafast Charge Recombination and Localisation in Transition Metal Oxides with Extended Visible Light Absorption." ECS Meeting Abstracts MA2022-02, no. 48 (October 9, 2022): 1835. http://dx.doi.org/10.1149/ma2022-02481835mtgabs.

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The development of materials with high activity for photocatalytic water splitting is a central challenge for the production of renewable hydrogen using sunlight. Owing to advantages such as low cost, elemental abundance, and chemical stability, transition metal oxides (TMOs) are some of the most widely used materials for this purpose. The most efficient systems developed to date reach solar-to-hydrogen conversion efficiencies (STH) of around 1%1 and are based on wide bandgap TMOs such as SrTiO3.2 Because such wide bandgap materials often absorb UV light only, TMOs with extended visible light absorption are key to bridge the activity gap towards the target for commercial applications,3 often considered to be 10% STH. While large research efforts have been devoted to TMOs with smaller bandgaps, efficiencies for such materials have typically remained relatively far from their theoretical limit. For example, Fe2O3 is one of the most studied TMOs in the field of solar fuel production, but it has so far reached only 1/3 of its theoretical maximum activity for water oxidation,4 raising the question of limitations of more fundamental nature. In this talk, I will discuss the links between ultrafast charge recombination and polaron formation in TMOs – two of the main processes considered to impose efficiency limitations. Firstly, Fe2O3, Cr2O3, and Co3O4, which have absorption onsets of around 2.1 eV, 1.9 eV, and 1.6 eV, respectively, are studied using time-resolved optical spectroscopic techniques to probe their excited state dynamics on a timescale of femtoseconds to seconds following light absorption. I will demonstrate how common photophysical features and dynamics suggest a shared pathway for the recombination and localisation of photogenerated charges in these materials, but with different branching ratios. Secondly, a comparison to wide bandgap metal oxides reveals a different relative importance of these recombination and localisation pathways compared to TMOs with smaller bandgaps. Taken together, a more general photophysical model emerges, providing insights into the performance limiting factors in TMOs, including those with extended visible light absorption. References: Wang, Q. et al. Scalable water splitting on particulate photocatalyst sheets with a solar-to-hydrogen energy conversion efficiency exceeding 1%. Nat. Mater. 1–3 (2016). Takata, T. et al. Photocatalytic water splitting with a quantum efficiency of almost unity. Nature 581, 411–414 (2020). Chen, S., Takata, T. & Domen, K. Particulate photocatalysts for overall water splitting. Nat. Rev. Mater. 2, 17050 (2017). Kim, J. Y. et al. Single-crystalline, wormlike hematite photoanodes for efficient solar water splitting. Sci. Rep. 3, 2681 (2013).

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Kang, Yihong, Hanhan Xie, Danni Liu, Ming Gao, Paul K. Chu, Seeram Ramakrishna, and Xue-Feng Yu. "Facile mass production of self-supported two-dimensional transition metal oxides for catalytic applications." Chemical Communications 55, no. 76 (2019): 11406–9. http://dx.doi.org/10.1039/c9cc06261k.

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Adedeji, A. V., S. D. Worsley, T. L. Baker, R. Mundle, A. K. Pradhan, A. C. Ahyi, and T. Isaacs-Smith. "Dynamic Properties of Spectrally Selective Reactively Sputtered Metal Oxides." MRS Proceedings 1494 (2013): 245–51. http://dx.doi.org/10.1557/opl.2013.593.

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ABSTRACTThin films of Transition Metal Oxides (TMOs) were deposited by reactive sputtering of pure transition metal targets in Argon-Oxygen gas mixture at elevated substrate temperature for efficient energy consumption. The atomic composition and thickness of the TMO films was determined by Rutherford Backscattering Spectroscopy (RBS). Optical transmittance and reflectance spectrum of the films on quartz substrate was measured with thin film measuring system at room temperature and slightly elevated temperature. The surface morphology and structure of the TMO films was determined with Atomic Force Microscope (AFM).

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Peng, Lei, Sheying Dong, Yaqi An, and Mengnan Qu. "Controllable generation of ZnO/ZnCo2O4 arising from bimetal–organic frameworks for electrochemical detection of naphthol isomers." Analyst 146, no. 10 (2021): 3352–60. http://dx.doi.org/10.1039/d1an00193k.

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This study developed new bicomponent-active transition metal oxides (TMOs) via pyrolysis of bimetal–organic frameworks Zn_xCo_6−x-BMOF with tunable “x” values for constructing an electrochemical sensor to detect naphthol isomers.

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Liang, Ruibin, Yongquan Du, Peng Xiao, Junyang Cheng, Shengjin Yuan, Yonglong Chen, Jian Yuan, and Jianwen Chen. "Transition Metal Oxide Electrode Materials for Supercapacitors: A Review of Recent Developments." Nanomaterials 11, no. 5 (May 10, 2021): 1248. http://dx.doi.org/10.3390/nano11051248.

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In the past decades, the energy consumption of nonrenewable fossil fuels has been increasing, which severely threatens human life. Thus, it is very urgent to develop renewable and reliable energy storage devices with features of environmental harmlessness and low cost. High power density, excellent cycle stability, and a fast charge/discharge process make supercapacitors a promising energy device. However, the energy density of supercapacitors is still less than that of ordinary batteries. As is known to all, the electrochemical performance of supercapacitors is largely dependent on electrode materials. In this review, we firstly introduced six typical transition metal oxides (TMOs) for supercapacitor electrodes, including RuO2, Co3O4, MnO2, ZnO, XCo2O4 (X = Mn, Cu, Ni), and AMoO4 (A = Co, Mn, Ni, Zn). Secondly, the problems of these TMOs in practical application are presented and the corresponding feasible solutions are clarified. Then, we summarize the latest developments of the six TMOs for supercapacitor electrodes. Finally, we discuss the developing trend of supercapacitors and give some recommendations for the future of supercapacitors.

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Yang, Cheng, Weiheng Gong, and Bo Zhang. "Research progress of transition metal compounds and composites in the field of supercapacitors." Highlights in Science, Engineering and Technology 53 (June 30, 2023): 228–34. http://dx.doi.org/10.54097/hset.v53i.9731.

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Supercapacitors are widely used in the field of energy storage because of their high power density and good cycle stability. The energy storage mechanism of different electrode materials is different, and the corresponding supercapacitors are also obviously different. In recent years, transition metallic compounds with high energy density and capacitance have attracted extensive attention. In this paper, the energy storage principles and research results of three main transition metal-based electrode materials (transition metal oxide (TMOs), Layered double hydroxides (LDHs) and transition metal sulfide (TMDs)) and the research progress of their composites are reviewed, and the future of transition metal-based electrode materials is prospected.

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Jo, Seunghwan, Young-Woo Lee, John Hong, and Jung Inn Sohn. "Simple and Facile Fabrication of Anion-Vacancy-Induced MoO3−X Catalysts for Enhanced Hydrogen Evolution Activity." Catalysts 10, no. 10 (October 14, 2020): 1180. http://dx.doi.org/10.3390/catal10101180.

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Advanced catalysts for clean hydrogen generation and storage offer an attractive possibility for developing a sustainable and ecofriendly future energy system. Transition metal oxides (TMO) are appealing candidates to be largely considered as electrode catalysts. However, for practical applications, there are still challenges—the intrinsic catalytic properties of TMOs should be further improved and TMOs should be synthesized by practical routes for cost-effective and scalable production of catalysts. Therefore, finding promising ways to fabricate highly active TMOs with outstanding electrochemical hydrogen evolution performance is required. Here, we present a direct and facile synthetic approach to successfully provide highly efficient MoO3−X catalysts with electrochemically active oxygen vacancies through a one-step thermal activation process on a Mo metal mesh. Variations in the oxidation states of molybdenum oxides can significantly increase the active sites of the catalysts and improve the electrochemical activity, making these oxide compounds suitable for hydrogen evolution reaction (HER). Compared to the bare Mo mesh and fully oxidized Mo (MoO3) electrodes, the fabricated MoO3−X electrode exhibits better electrochemical performance in terms of overpotentials and Tafel slope, as well as the electrochemical 1000 cycling stability, confirming the improved HER performance of MoO3−X. This provides new insight into the simple procedure suitable for the large-production supply.

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Ahuja, Preety, Sanjeev Kumar Ujjain, Rajni Kanojia, and Pankaj Attri. "Transition Metal Oxides and Their Composites for Photocatalytic Dye Degradation." Journal of Composites Science 5, no. 3 (March 15, 2021): 82. http://dx.doi.org/10.3390/jcs5030082.

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Transition metal oxides (TMO) and their carbon composites have become a glittering upcoming material science candidate. Their interesting properties, such as their meticulous morphology, plentiful availability, flexible surface chemistry along with outstanding mechanical, thermal, and optical properties make them ideal for efficient photocatalytic dye degradation. An extensive range of TMO, and their carbon composites are reviewed highlighting the progression and opportunities for the photocatalytic degradation of dyes. Here, we concisely describe the numerous techniques to extend the optical absorption of these TMOs involving dye sensitization, metal doping, etc. Besides this, an overview of all aspects of dye degradation along with the prevailing challenges for future utilization and development of such nanocomposites towards highly efficient dye degradation system are also reported.

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Li, Shuang, Yu-Chang Hou, Yuan-Ru Guo, and Qing-Jiang Pan. "Uranium-Doped Zinc, Copper, and Nickel Oxides for Enhanced Catalytic Conversion of Furfural to Furfuryl Alcohol: A Relativistic DFT Study." Molecules 27, no. 18 (September 18, 2022): 6094. http://dx.doi.org/10.3390/molecules27186094.

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Transition metal oxides (TMOs) and actinide ones (AnOs) have been widely applied in catalytic reactions due to their excellent physicochemical properties. However, the reaction pathway and mechanism, especially involving TM–An heterometallic centers, remain underexplored. In this respect, relativistic density functional theory (DFT) was used to examine uranium-doped zinc, copper, and nickel oxides for their catalytic activity toward the conversion of furfural to furfuryl alcohol. A comparison was made with their undoped TMOs. It was found that the three TMOs were capable of catalyzing the reaction, where the free energies of adsorption, hydrogenation, and desorption fell between −33.93 and 45.00 kJ/mol. The uranium doping extremely strengthened the adsorption of CuO-U and NiO-U toward furfural, making hydrogenation or desorption much harder. Intriguingly, ZnO-U showed the best catalytic performance among all six catalyst candidates, as its three reaction energies were very small (−10.54–8.12 kJ/mol). The reaction process and mechanism were further addressed in terms of the geometrical, bonding, charge, and electronic properties.

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Quispe-Garrido, Vanessa, Gabriel Antonio Cerron-Calle, Antony Bazan-Aguilar, José G. Ruiz-Montoya, Elvis O. López, and Angélica M. Baena-Moncada. "Advances in the design and application of transition metal oxide-based supercapacitors." Open Chemistry 19, no. 1 (January 1, 2021): 709–25. http://dx.doi.org/10.1515/chem-2021-0059.

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Abstract In the last years, supercapacitors (SCs) have been proposed as a promising alternative to cover the power density deficiency presented in batteries. Electrical double-layer SCs, pseudocapacitors, and hybrid supercapacitors (HSCs) have shown very attractive features such as high-power density, long cycle life, and tunable specific capacitance. The advances of these energy storage devices made by transition metal oxides (TMOs) and their production in pseudocapacitors and HSCs depend on chemical composition, crystalline structure, morphology, theoretical capacitance, and oxidation states. In this way, this critical review considers several metal oxides (RuO2, MnO2, V2O5, and Co3O4) and their different configurations with diverse carbon-based materials. Energy storage mechanisms and fundamental principles to understand the promising effect of metal oxides in SCs devices are thoroughly described. Special attention as regards to the energy storage mechanisms relative to the specific capacitance values is presented in the reviewed articles. This review envisages the TMO as a key component to obtain high specific capacitance SCs.

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Yin, Zongyou, Moshe Tordjman, Youngtack Lee, Alon Vardi, Rafi Kalish, and Jesús A. del Alamo. "Enhanced transport in transistor by tuning transition-metal oxide electronic states interfaced with diamond." Science Advances 4, no. 9 (September 2018): eaau0480. http://dx.doi.org/10.1126/sciadv.aau0480.

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High electron affinity transition-metal oxides (TMOs) have gained a central role in two-dimensional (2D) electronics by enabling unprecedented surface charge doping efficiency in numerous exotic 2D solid-state semiconductors. Among them, diamond-based 2D electronics are entering a new era by using TMOs as surface acceptors instead of previous molecular-like unstable acceptors. Similarly, surface-doped diamond with TMOs has recently yielded record sheet hole concentrations (2 × 1014 cm−2) and launched the quest for its implementation in microelectronic devices. Regrettably, field-effect transistor operation based on this surface doping has been so far disappointing due to fundamental material obstacles such as (i) carrier scattering induced by nonhomogeneous morphology of TMO surface acceptor layer, (ii) stoichiometry changes caused by typical transistor fabrication process, and (iii) carrier transport loss due to electronic band energy misalignment. This work proposes and demonstrates a general strategy that synergistically surmounts these three barriers by developing an atomic layer deposition of a hydrogenated MoO3 layer as a novel efficient surface charge acceptor for transistors. It shows high surface uniformity, enhanced immunity to harsh fabrication conditions, and benefits from tunable electronic gap states for improving carrier transfer at interfaces. These breakthroughs permit crucial integration of TMO surface doping into transistor fabrication flows and allow outperforming electronic devices to be reached.

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Kwon, Minjae, Jongyoon Park, and Jongkook Hwang. "Conversion reaction-based transition metal oxides as anode materials for lithium ion batteries: recent progress and future prospects." Ceramist 25, no. 2 (June 30, 2022): 218–46. http://dx.doi.org/10.31613/ceramist.2022.25.2.03.

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The rapid increase in demand for high-performance lithium ion batteries (LIBs) has prompted the development of high capacity anode materials that can replace/complement the commercial graphite. Transition metal oxides (TMOs) have attracted great attention as high capacity anode materials because they can store multiple lithium ions (electrons) per unit formula via conversion reaction, resulting in high specific capacity (700-1,200 mAh g<sup>-1</sup>) and volumetric capacity (4,000-5,500 mAh cm<sup>-3</sup>). In addition, TMOs are cheap, earth-abundant, non-toxic and environmentally friendly. However, there have been no reports of practical LIBs using conversion-based TMO anodes, because of several major problems such as large voltage hysteresis, low initial Coulombic efficiency (large initial capacity loss), low electrical conductivity, and large volume changes (100~200%). This review summarizes the recent progress, challenges and opportunities for TMO anode materials. The conversion reaction mechanism, problems and solutions of TMO anode materials are discussed. Considering iron oxide as a promising candidate, future research directions and prospects for the practical use of TMO for LIB are presented.

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Zhang, Ying, Meiwen Zhu, Qing Wei, and Mingxi Wang. "Removing Chlorobenzene via the Synergistic Effects of Adsorption and Catalytic Oxidation over Activated Carbon Fiber Loaded with Transition Metal Oxides." Atmosphere 13, no. 12 (December 9, 2022): 2074. http://dx.doi.org/10.3390/atmos13122074.

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This study focused on the elimination of chlorobenzene by dual adsorption/catalytic oxidation over activated carbon fibers (ACFs) loaded with transition metal oxides (TMOs). The TMOs were successfully loaded on the ACFs by the incipient wetness impregnation method, which has the advantages of easy preparation, low cost, and size uniformity. The removal effects for chlorobenzene (CB) were investigated on pristine ACFs and TMOs@ACFs in a fix-bed reactor. The adsorption/catalytic oxidation experiments result demonstrated that ACFs can be used as a very efficient adsorbent for the removal of low-concentration CB at the low temperature of 120 °C; the breakthrough time of CB over pristine ACFs can reach 15 h at an inlet concentration of 5000 ppmv and space velocity of 20,000 h−1. As the bed temperature rose above 175 °C, the CB removal mainly contributed to the catalytic oxidation of MnO2; a preferable CB removal ratio was achieved at higher temperatures in the presence of more MnO2. Therefore, CB can be effectively removed by the dual adsorbent/catalyst of MnO2@ACF at the full temperature range below 300 °C.

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Yi, Di, Jian Liu, Shang-Lin Hsu, Lipeng Zhang, Yongseong Choi, Jong-Woo Kim, Zuhuang Chen, et al. "Atomic-scale control of magnetic anisotropy via novel spin–orbit coupling effect in La2/3Sr1/3MnO3/SrIrO3 superlattices." Proceedings of the National Academy of Sciences 113, no. 23 (May 19, 2016): 6397–402. http://dx.doi.org/10.1073/pnas.1524689113.

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Magnetic anisotropy (MA) is one of the most important material properties for modern spintronic devices. Conventional manipulation of the intrinsic MA, i.e., magnetocrystalline anisotropy (MCA), typically depends upon crystal symmetry. Extrinsic control over the MA is usually achieved by introducing shape anisotropy or exchange bias from another magnetically ordered material. Here we demonstrate a pathway to manipulate MA of 3d transition-metal oxides (TMOs) by digitally inserting nonmagnetic 5d TMOs with pronounced spin–orbit coupling (SOC). High-quality superlattices comprising ferromagnetic La2/3Sr1/3MnO3 (LSMO) and paramagnetic SrIrO3 (SIO) are synthesized with the precise control of thickness at the atomic scale. Magnetic easy-axis reorientation is observed by controlling the dimensionality of SIO, mediated through the emergence of a novel spin–orbit state within the nominally paramagnetic SIO.

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Alheshibri, Muidh, H. M. Albetran, B. H. Abdelrahman, A. Al-Yaseri, N. Yekeen, and I. M. Low. "Wettability of Nanostructured Transition-Metal Oxide (Al2O3, CeO2, and AlCeO3) Powder Surfaces." Materials 15, no. 16 (August 10, 2022): 5485. http://dx.doi.org/10.3390/ma15165485.

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Wettability has been the focal point of many studies in metal oxide materials due to their applications in water–gas shift reactions, organic reactions, thermochemical water splitting, and photocatalysis. This paper presents the results of systematic experimental studies on the wettability of surfaces of nanostructured transition-metal oxides (TMOs) (Al2O3, CeO2, and AlCeO3). The wettability of nanoparticles was investigated by measuring contact angles of different concentrations of water-based nanofluids (0.05–0.1 wt%) on the glass slide. The morphology, the heterostructure, and the nature of incorporated nanoparticles were confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Characteristic diffraction patterns of the nanomaterials were evaluated using energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The contact angles of water–Al2O3, water–CeO2, and water–AlCeO3 were measured as 77.5 ± 5°, 89.8 ± 4°, and 69.2 ± 1°, respectively. This study suggests that AlCeO3 is strongly water-wet (hydrophilic), while CeO2 is weakly water-wet (hydrophobic). It further demonstrated that the sizes and compositions of the nanoparticles are key parameters that influence their wetting behaviors.

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Meng, Jie, Nengjie Feng, Fan Fang, Hui Wan, and Guofeng Guan. "Transition metal oxides (TMOs) supported on ordered mesoporous Ce0.1Mn0.9Oδ as high-efficient catalysts for toluene combustion." Materials Letters 263 (March 2020): 127230. http://dx.doi.org/10.1016/j.matlet.2019.127230.

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Carrow, James K., Lauren M. Cross, Robert W. Reese, Manish K. Jaiswal, Carl A. Gregory, Roland Kaunas, Irtisha Singh, and Akhilesh K. Gaharwar. "Widespread changes in transcriptome profile of human mesenchymal stem cells induced by two-dimensional nanosilicates." Proceedings of the National Academy of Sciences 115, no. 17 (April 11, 2018): E3905—E3913. http://dx.doi.org/10.1073/pnas.1716164115.

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Two-dimensional nanomaterials, an ultrathin class of materials such as graphene, nanoclays, transition metal dichalcogenides (TMDs), and transition metal oxides (TMOs), have emerged as a new generation of materials due to their unique properties relative to macroscale counterparts. However, little is known about the transcriptome dynamics following exposure to these nanomaterials. Here, we investigate the interactions of 2D nanosilicates, a layered clay, with human mesenchymal stem cells (hMSCs) at the whole-transcriptome level by high-throughput sequencing (RNA-seq). Analysis of cell–nanosilicate interactions by monitoring changes in transcriptome profile uncovered key biophysical and biochemical cellular pathways triggered by nanosilicates. A widespread alteration of genes was observed due to nanosilicate exposure as more than 4,000 genes were differentially expressed. The change in mRNA expression levels revealed clathrin-mediated endocytosis of nanosilicates. Nanosilicate attachment to the cell membrane and subsequent cellular internalization activated stress-responsive pathways such as mitogen-activated protein kinase (MAPK), which subsequently directed hMSC differentiation toward osteogenic and chondrogenic lineages. This study provides transcriptomic insight on the role of surface-mediated cellular signaling triggered by nanomaterials and enables development of nanomaterials-based therapeutics for regenerative medicine. This approach in understanding nanomaterial–cell interactions illustrates how change in transcriptomic profile can predict downstream effects following nanomaterial treatment.

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Xiong, Wanning, Jie Ouyang, Xiaoman Wang, Ziheng Hua, Linlin Zhao, Mengyao Li, Yuxin Lu, et al. "Semi-Embedding Zn-Co3O4 Derived from Hybrid ZIFs into Wood-Derived Carbon for High-Performance Supercapacitors." Molecules 27, no. 23 (December 5, 2022): 8572. http://dx.doi.org/10.3390/molecules27238572.

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Transition metal oxides (TMOs) can provide high theoretical capacitance due to the change of multiple valence states of transition metals. However, their intrinsic drawbacks, including poor electrical conductivity, lower energy density, and huge volume expansion, will result in the pulverization of electrode materials and restricted electrochemical kinetics, thus leading to poor rate capability and rapid capacity fading. Composite electrodes based on transition metal oxides and carbon-based materials are considered to be promising candidates for overcoming these limitations. Herein, we reported a preparation method of hybrid ZIFs derived Zn-doped Co3O4/carbon (Zn-Co3O4/C-230) particles semi-embedded in wood-derived carbon skeleton for integrated electrodes. A large specific surface area, excellent conductivity, and electrochemical stability provide a larger electrochemical activity and potential window for the electrode. Prepared Zn-Co3O4@CW-230 electrode (0.6 mm thick) displays ultrahigh area specific capacitances of 7.83 and 6.46 F cm−2 at the current densities of 5 and 30 mA cm−2, respectively. Moreover, a symmetric supercapacitor assembled by two identical Zn-Co3O4@CW-230 electrodes delivers a superior area-specific capacitance of 2.61 F cm−2 at the current densities of 5 mA cm−2 and great energy densities of 0.36 mWh cm−2 (6.0 mWh cm−3) at 2.5 mW cm−2, while maintaining 97.3% of initial capacitance over 10,000 cycles. It notably outperforms those of most carbon-based metal oxides, endowing the Zn-Co3O4@CW-230 with extensive prospects for practical application.

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Khidzir, S. M., K. N. Ibrahim, and W. A. T. Wan Abdullah. "GW approximation study of late transition metal oxides: Spectral function clusters around Fermi energy as the mechanism behind smearing in momentum density." Modern Physics Letters B 30, no. 14 (May 29, 2016): 1650162. http://dx.doi.org/10.1142/s0217984916501621.

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Momentum density studies are the key tool in Fermiology in which electronic structure calculations have proven to be the integral underlying methodology. Agreements between experimental techniques such as Compton scattering experiments and conventional density functional calculations for late transition metal oxides (TMOs) prove elusive. In this work, we report improved momentum densities of late TMOs using the GW approximation (GWA) which appears to smear the momentum density creating occupancy above the Fermi break. The smearing is found to be largest for NiO and we will show that it is due to more spectra surrounding the NiO Fermi energy compared to the spectra around the Fermi energies of FeO and CoO. This highlights the importance of the positioning of the Fermi energy and the role played by the self-energy term to broaden the spectra and we elaborate on this point by comparing the GWA momentum densities to their LDA counterparts and conclude that the larger difference at the intermediate level shows that the self-energy has its largest effect in this region. We finally analyzed the quasiparticle renormalization factor and conclude that an increase of electrons in the [Formula: see text]-orbital from FeO to NiO plays a vital role in changing the magnitude of electron correlation via the self-energy.

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Wang, Bingning, Seoung-Bum Son, Pavan Badami, Stephen E. Trask, Daniel Abraham, Yang Qin, Zhenzhen Yang, Xianyang Wu, Andrew Jansen, and Chen Liao. "Understanding and Mitigating the Dissolution and Delamination Issues Encountered with High-Voltage LiNi0.5Mn1.5O4." Batteries 9, no. 9 (August 24, 2023): 435. http://dx.doi.org/10.3390/batteries9090435.

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In our initial study on the high-voltage 5 V cobalt-free spinel LiNi0.5Mn1.5O4 (LNMO) cathode, we discovered a severe delamination issue in the laminates when cycled at a high upper cut-off voltage (UCV) of 4.95 V, especially when a large cell format was used. This delamination problem prompted us to investigate further by studying the transition metal (TM) dissolution mechanism of cobalt-free LNMO cathodes, and as a comparison, some cobalt-containing lithium nickel manganese cobalt oxides (NMC) cathodes, as the leachates from the soaking experiment might be the culprit for the delamination. Unlike other previous reports, we are interested in the intrinsic stability of the cathode in the presence of a baseline Gen2 electrolyte consisting of 1.2 M of LiPF6 in ethylene carbonate/ethyl methyl carbonate (EC/EMC), similar to a storage condition. The electrode laminates (transition metal oxides, transition metal oxides, TMOs, coated on an Al current collector with a loading level of around 2.5 mAh/cm2) or the TMO powders (pure commercial quality spinel LNMO, NMC, etc.) were stored in the baseline solution, and the transition metal dissolution was studied through nuclear magnetic resonance, such as 1H NMR, 19F NMR, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma mass spectrometry (ICP-MS). Significant electrolyte decomposition was observed and could be the cause that leads to the TM dissolution of LNMO. To address this TM dissolution, additives were introduced into the baseline electrolyte, effectively alleviating the issue of TM dissolution. The results suggest that the observed delamination is caused by electrolyte decompositions that lead to etching, and additives such as lithium difluorooxalato borate and p-toluenesulfonyl isocyanate can alleviate this issue by forming a firm cathode electrolyte interface. This study provides a new perspective on cell degradation induced by electrode/electrolyte interactions under storage conditions.

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Mendieta-Reyes, Néstor E., Alejandra S. Lozano-Pérez, and Carlos A. Guerrero-Fajardo. "Insights of Fe2O3 and MoO3 Electrodes for Electrocatalytic CO2 Reduction in Aprotic Media." International Journal of Molecular Sciences 23, no. 21 (November 2, 2022): 13367. http://dx.doi.org/10.3390/ijms232113367.

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Transition metal oxides (TMO) have been successfully used as electrocatalytically active materials for CO2 reduction in some studies. Because of the lack of understanding of the catalytic behavior of TMOs, electrochemical methods are used to investigate the CO2 reduction in thin-film nanostructured electrodes. In this context, nanostructured thin films of Fe2O3 and MoO3 in an aprotic medium of acetonitrile have been used to study the CO2 reduction reaction. In addition, a synergistic effect between CO2 and the TMO surface is observed. Faradic cathodic processes not only start at lower potentials than those reported with metal electrodes, but also an increase in capacitive currents is observed, which is directly related to an increase in oxygen vacancies. Finally, the results obtained show CO as a product of the reduction.

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Jaiswal, A. K., R. Schneider, M. Le Tacon, and D. Fuchs. "Magnetotransport of SrIrO₃-based heterostructures." AIP Advances 12, no. 3 (March 1, 2022): 035120. http://dx.doi.org/10.1063/9.0000325.

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Transition-metal oxide (TMO) based heterostructures provide fertile playground to explore or functionalize novel quantum materials. In this regard, the combination of 3 d and 5 d TMOs have gained special interest because of the simultaneous appearance of strong spin–orbit coupling and electron correlation at the interface of those heterostructures. Artificial breaking of the inversion symmetry in heterostructures may also result in a distinct interfacial Dzyaloshinskii-Moriya interaction (DMI) and the formation of non-collinear magnetic spin structures in case of magnetic TMOs. Among the 5 d TMOs, SrIrO3 (SIO) has gained significant attention because of its large spin–orbit coupling and the semi-metallic ground state, which are highly susceptible to structural distortions. Here, we report on the preparation and the characterisation of structural, electronic and magnetic properties of epitaxial heterostructures consisting of the 5 d TMO SIO and the 3 d antiferromagnetic insulator LaFeO3.

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Kasinathan, Dhivyaprasath, Praveena Prabhakar, Preethi Muruganandam, Biny R. Wiston, Ashok Mahalingam, and Ganesan Sriram. "Solution Processed NiO/MoS2 Heterostructure Nanocomposite for Supercapacitor Electrode Application." Energies 16, no. 1 (December 28, 2022): 335. http://dx.doi.org/10.3390/en16010335.

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Metal oxide and metal dichalcogenide heterostructure composites are promising candidates for electrochemical use. In this study, a hybrid heterostructure composite electrode material was made using a straightforward hydrothermal process using transition metal oxide (NiO) and metal dichalcogenide (MoS2). The surface of the flower-like structured MoS2 was grown with granular structured NiO, and this heterostructure composite exhibited considerably improved specific capacitance when compared to the pure NiO and MoS2 materials. The pseudocapacitive performance was effectively supported by the heterostructure combination of transition metal oxide (TMOs) and metal dichalcogenide (MDC), which greatly improved ion transport within the material and storage. At a current density of 1 A/g, the prepared heterostructure composite electrode material exhibited a specific capacitance of 289 F/g, and, after 2000 cycles, the capacitance retained 101% of its initial value. The symmetric device was constructed and put through tests using LED light. This finding opens up a new avenue for the quickly increasing the field of heterostructure materials.

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Stylianakis, Minas M. "Optoelectronic Nanodevices." Nanomaterials 10, no. 3 (March 13, 2020): 520. http://dx.doi.org/10.3390/nano10030520.

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Over the last decade, novel materials such as graphene derivatives, transition metal dichalcogenides (TMDs), other two-dimensional (2D) layered materials, perovskites, as well as metal oxides and other metal nanostructures have centralized the interest of the scientific community [...]

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Song, Ge, Shan Cong, and Zhigang Zhao. "Defect engineering in semiconductor-based SERS." Chemical Science 13, no. 5 (2022): 1210–24. http://dx.doi.org/10.1039/d1sc05940h.

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Defect engineering strategies are used to boost the SERS activity of a wide variety of semiconductors including metal oxides, nitrides, carbon materials and transition metal dichalcogenides (TMDs), as discussed in this perspective.

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Koshtyal, Yury, Ilya Mitrofanov, Denis Nazarov, Oleg Medvedev, Artem Kim, Ilya Ezhov, Aleksander Rumyantsev, Anatoly Popovich, and Maxim Yu Maximov. "Atomic Layer Deposition of Ni-Co-O Thin-Film Electrodes for Solid-State LIBs and the Influence of Chemical Composition on Overcapacity." Nanomaterials 11, no. 4 (April 2, 2021): 907. http://dx.doi.org/10.3390/nano11040907.

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Nanostructured metal oxides (MOs) demonstrate good electrochemical properties and are regarded as promising anode materials for high-performance lithium-ion batteries (LIBs). The capacity of nickel-cobalt oxides-based materials is among the highest for binary transition metals oxide (TMOs). In the present paper, we report the investigation of Ni-Co-O (NCO) thin films obtained by atomic layer deposition (ALD) using nickel and cobalt metallocenes in a combination with oxygen plasma. The formation of NCO films with different ratios of Ni and Co was provided by ALD cycles leading to the formation of nickel oxide (a) and cobalt oxide (b) in one supercycle (linear combination of a and b cycles). The film thickness was set by the number of supercycles. The synthesized films had a uniform chemical composition over the depth with an admixture of metallic nickel and carbon up to 4 at.%. All samples were characterized by a single NixCo1-xO phase with a cubic face-centered lattice and a uniform density. The surface of the NCO films was uniform, with rare inclusions of nanoparticles 15–30 nm in diameter. The growth rates of all films on steel were higher than those on silicon substrates, and this difference increased with increasing cobalt concentration in the films. In this paper, we propose a method for processing cyclic voltammetry curves for revealing the influence of individual components (nickel oxide, cobalt oxide and solid electrolyte interface—SEI) on the electrochemical capacity. The initial capacity of NCO films was augmented with an increase of nickel oxide content.

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Mei, Jun, Yuanwen Zhang, Ting Liao, Ziqi Sun, and Shi Xue Dou. "Strategies for improving the lithium-storage performance of 2D nanomaterials." National Science Review 5, no. 3 (July 21, 2017): 389–416. http://dx.doi.org/10.1093/nsr/nwx077.

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Abstract 2D nanomaterials, including graphene, transition metal oxide (TMO) nanosheets, transition metal dichalcogenide (TMD) nanosheets, etc., have offered an appealing and unprecedented opportunity for the development of high-performance electrode materials for lithium-ion batteries (LIBs). Although significant progress has been made on 2D nanomaterials for LIB applications in the recent years, some major challenges still exist for the direct use of these sheet-like nanomaterials, such as their serious self-agglomerating tendency during electrode fabrication and low conductivity as well as the large volume changes over repeated charging–discharging cycles for most TMOs/TMDs, which have resulted in large irreversible capacity, low initial Coulombic efficiency and fast capacity fading. To address these issues, considerable progress has been made in the exploitation of 2D nanosheets for enhanced lithium storage. In this review, we intend to summarize the recent progress on the strategies for enhancing the lithium-storage performance of 2D nanomaterials, including hybridization with conductive materials, surface/edge functionalization and structural optimization. These strategies for manipulating the structures and properties of 2D nanomaterials are expected to meet the grand challenges for advanced nanomaterials in clean energy applications and thus provide access to exciting materials for achieving high-performance next-generation energy-storage devices.

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Browne, Michelle P., Joana M. Vasconcelos, João Coelho, Maria O'Brien, Aurelie A. Rovetta, Eoin K. McCarthy, Hugo Nolan, et al. "Improving the performance of porous nickel foam for water oxidation using hydrothermally prepared Ni and Fe metal oxides." Sustainable Energy & Fuels 1, no. 1 (2017): 207–16. http://dx.doi.org/10.1039/c6se00032k.

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Zuo, Wenhua, Guiliang Xu, and Khalil Amine. "The Air Stability of Sodium Layered Oxide Cathodes." ECS Meeting Abstracts MA2022-02, no. 7 (October 9, 2022): 2594. http://dx.doi.org/10.1149/ma2022-0272594mtgabs.

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Sodium-ion batteries (NIBs) are listed as one of the ideal alternatives for lithium-ion batteries (LIBs), due to the abundant sodium resources, cost-effective electrode materials of NIBs, and same architecture of NIBs to LIBs. To enable the practical implementation of NIBs, advanced cathodes with higher energy/power densities, better safety and cycle life, as well as lower cost are required. Layered lithium transition metal oxides (LiTMO2) are one of the most successful cathode materials for commercial LIBs. Similarly, layered sodium transition metal oxides (NaxTMO2, also termed as sodium layered oxides) are of particular interest for commercial NIBs owing to their high specific capacity, a wide variety of redox-active elements, and the possibility for the manufacturers to employ established synthesis processes as their lithium counterparts. Sodium layered oxides are built up by ordered stacking of alternate alkali-metal (Na+) layers and transition metal layers (TmO2). The two-dimensional structure makes them the natural hosts for alkali-metal ions and other ions or small molecules, such as H2O. Therefore, when exposed to moist atmospheres, layered oxide materials tend to react with H2O which adsorbed on their surface and thus deteriorate their structure and electrochemical performances. Accordingly, the air-sensitive sodium layered oxides should be well protected from the moist atmospheres, rendering a higher manufacturing and preservation cost. Here, based on the reaction mechanisms, critical influencing factors, and modification methods of layered oxides in moisture, we try to reach a comprehensive understanding of the air-stability of sodium layered oxides. Moreover, future efforts to resolve the air-stability of sodium layered oxides from Argonne National Laboratory will be also presented. References 1. Han, M. H.; Gonzalo, E.; Singh, G.; Rojo, T. A comprehensive review of sodium layered oxides: powerful cathodes for Na-ion batteries. Energy Environ. Sci. 2015, 8, 81-102. 2. Zuo, W.; Qiu, J.; Liu, X.; Ren, F.; Liu, H.; He, H.; Luo, C.; Li, J.; Ortiz, G. F.; Duan, H.; Liu, J.; Wang, M. S.; Li, Y.; Fu, R.; Yang, Y. The stability of P2-layered sodium transition metal oxides in ambient atmospheres. Commun. 2020, 11, 3544. 3. Xu, G. L.; Liu, X.; Zhou, X.; Zhao, C.; Hwang, I.; Daali, A.; Yang, Z.; Ren, Y.; Sun, C. J.; Chen, Z.; Liu, Y.; Amine, K. Native lattice strain induced structural earthquake in sodium layered oxide cathodes. Commun. 2022, 13, 436. 4. Zuo, W.; Xiao, Z.; Zarrabeitia, M.; Xue, X.; Yang, Y.; Passerini, S. Guidelines for Air-Stable Lithium/Sodium Layered Oxide Cathodes. ACS Materials Letters 2022, 4, 1074-1086. 5. Fu, F.; Liu, X.; Fu, X.; Chen, H.; Huang, L.; Fan, J.; Le, J.; Wang, Q.; Yang, W.; Ren, Y.; Amine, K.; Sun, S. G.; Xu, G. L. Entropy and crystal-facet modulation of P2-type layered cathodes for long-lasting sodium-based batteries. Commun. 2022, 13, 2826.

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Soheyli, Ehsan, Mohammad Hossein Hekmatshoar, and Farshad Parcham. "Optical and structural characterization of quadruplet and quintuplet molybdenum-containing phosphate glasses." Modern Physics Letters B 30, no. 18 (July 10, 2016): 1650270. http://dx.doi.org/10.1142/s0217984916502705.

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In this work, vitreous samples were prepared in two series by normal melt-quenching technique and under controlled conditions. The amorphous nature of specimens was confirmed using XRD spectra. To perform FT-IR and UV-vis studies, the thin blown films were also prepared. Different ratios of transition metals are assumed to cause depolymerization of the phosphate glass network. Infrared spectra showed absorption bands related to characteristic bonds of phosphate. The P=O bond at about 1200 cm[Formula: see text] was observed, as a direct consequence of meta-phosphate bond group. The almost unchanged peak position and intensity of P=O bond (in the presence of two transition metal ions) indicated the glass modifying nature of transition metal oxides (TMOs). The spectra of two series are almost identical, except for 890–1100 cm[Formula: see text] range, which can be attributed to presence of second TMO in the first glass series. UV-vis spectra also showed that the absorption edge, optical band gap and Urbach energy of the prepared samples are highly dependent on the kind and percentage of their reagents. The most striking result of UV-vis measurements was increasing and decreasing of optical band gap in the first and the second series with MoO3 content, respectively. The shape of the absorption edge (a plot of [Formula: see text] versus [Formula: see text]) demonstrated the indirect nature of the band gap in the prepared specimens.

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Siddiqui, Safina-E.-Tahura, Md Arafat Rahman, Jin-Hyuk Kim, Sazzad Bin Sharif, and Sourav Paul. "A Review on Recent Advancements of Ni-NiO Nanocomposite as an Anode for High-Performance Lithium-Ion Battery." Nanomaterials 12, no. 17 (August 25, 2022): 2930. http://dx.doi.org/10.3390/nano12172930.

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Recently, lithium-ion batteries (LIBs) have been widely employed in automobiles, mining operations, space applications, marine vessels and submarines, and defense or military applications. As an anode, commercial carbon or carbon-based materials have some critical issues such as insufficient charge capacity and power density, low working voltage, deadweight formation, short-circuiting tendency initiated from dendrite formation, device warming up, etc., which have led to a search for carbon alternatives. Transition metal oxides (TMOs) such as NiO as an anode can be used as a substitute for carbon material. However, NiO has some limitations such as low coulombic efficiency, low cycle stability, and poor ionic conductivity. These limitations can be overcome through the use of different nanostructures. This present study reviews the integration of the electrochemical performance of binder involved nanocomposite of NiO as an anode of a LIB. This review article aims to epitomize the synthesis and characterization parameters such as specific discharge/charge capacity, cycle stability, rate performance, and cycle ability of a nanocomposite anode. An overview of possible future advances in NiO nanocomposites is also proposed.

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Chen, Shuang, Shukun Wang, Yunyun Dong, Hongmei Du, Jinsheng Zhao, and Pengfang Zhang. "Anchoring NiO Nanosheet on the Surface of CNT to Enhance the Performance of a Li-O2 Battery." Nanomaterials 12, no. 14 (July 13, 2022): 2386. http://dx.doi.org/10.3390/nano12142386.

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Li2O2, as the cathodic discharge product of aprotic Li-O2 batteries, is difficult to electrochemically decompose. Transition-metal oxides (TMOs) have been proven to play a critical role in promoting the formation and decomposition of Li2O2. Herein, a NiO/CNT catalyst was prepared by anchoring a NiO nanosheet on the surface of CNT. When using the NiO/CNT as a cathode catalyst, the Li-O2 battery had a lower overpotential of 1.2 V and could operate 81 cycles with a limited specific capacity of 1000 mA h g−1 at a current density of 100 mA g−1. In comparison, with CNT as a cathodic catalyst, the battery could achieve an overpotential of 1.64 V and a cycling stability of 66 cycles. The introduction of NiO effectively accelerated the generation and decomposition rate of Li2O2, further improving the battery performance. SEM and XRD characterizations confirmed that a Li2O2 film formed during the discharge process and could be fully electrochemical decomposed in the charge process. The internal network and nanoporous structure of the NiO/CNT catalyst could provide more oxygen diffusion channels and accelerate the decomposition rate of Li2O2. These merits led to the Li-O2 battery’s better performance.

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Iqbal, Sajid, Tanveer Hussain Bokhari, Shoomaila Latif, Muhammad Imran, Ayesha Javaid, and Liviu Mitu. "Structural and Morphological Studies of V2O5/MWCNTs and ZrO2/MWCNTs Composites as Photocatalysts." Journal of Chemistry 2021 (May 18, 2021): 1–11. http://dx.doi.org/10.1155/2021/9922726.

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The present study outlines the synthesis of transition metal oxide- (TMO-) multiwall carbon nanotubes- (MWCNTs-) based composites for photocatalytic application. MWCNTs were functionalized/purified by treating with H2SO4 and HNO3 to improve their dispersion in water. The TMOs (ZrO2, V2O5) were decorated on MWCNTs by the hydrothermal method to yield V2O5/MWCNTs and ZrO2/MWCNTs composites. Subsequently, these composites were characterized for their structural/morphological studies by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Photocatalytic activities of TMO/MWCNTs composites were investigated by degradation phenomenon of methylene blue (MB) dye in aqueous solution. It was observed that the prepared composites best performed in the presence of H2O2 under ultraviolet irradiation. The maximum observed degradation efficiencies for ZrO2/MWCNTs and V2O5/MWCNTs were 49% and 96%, respectively.

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Lucovsky, G., D. Zeller, and J. L. Whitten. "O-vacancies in transition metal (TM) oxides: Coordination and local site symmetry of transition and negative ion states in TM2O3 and TMO2 oxides." Microelectronic Engineering 88, no. 7 (July 2011): 1471–74. http://dx.doi.org/10.1016/j.mee.2011.03.153.

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Basnet, Pradip, M. Arslan Shehzad, and Xi-Bo Li. "Novel Synthesis and Applications of Metal, Metal Oxides (MOs), and Transition Metal Dichalcogenides (TMDs) for Energy, Sensing, and Memory Applications." Advances in Materials Science and Engineering 2019 (November 7, 2019): 1–2. http://dx.doi.org/10.1155/2019/4163786.

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Wu, Qiangqiang, Meizan Jing, Yuechang Wei, Zhen Zhao, Xindong Zhang, Jing Xiong, Jian Liu, Weiyu Song, and Jianmei Li. "High-efficient catalysts of core-shell structured Pt@transition metal oxides (TMOs) supported on 3DOM-Al2O3 for soot oxidation: The effect of strong Pt-TMO interaction." Applied Catalysis B: Environmental 244 (May 2019): 628–40. http://dx.doi.org/10.1016/j.apcatb.2018.11.094.

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Aleithan, Shrouq H., Kawther Al-Amer, Zakia Alhashem, Nada A. Alati, Zainab H. Alabbad, and Khan Alam. "Growth of MoS₂ films: High-quality monolayered and multilayered material." AIP Advances 12, no. 7 (July 1, 2022): 075220. http://dx.doi.org/10.1063/5.0086228.

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Transition-metal-dichalcogenide materials (TMDs) are proceeding toward future nanoelectronic devices as comprehensive research in this domain proves their extraordinary properties and potential for application in diverse fields. There are associated challenges related to the quality of grown material, grain size, and adaptiveness to a selected substrate, and chemical vapor deposition is considered the ideal technique in these regards. Salt-assisted growth of two-dimensional TMDs has recently solved some growth issues associated with the high melting points of some oxides and the low vapor pressure, which leads to limitations in the growth area. In the current study, NaCl-assisted growth is used to produce high-quality monolayered films on Si/SiO2 and multilayered films of MoS2 on fluorine-doped tin oxide. An empirical methodology was used to determine optimal conditions for sample growth. Factors such as precursor weights and ratios, temperature, and sulfurization were investigated with respect to preparing samples for exploitable applications.

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Chen, Ying, Yuling Hu, and Gongke Li. "A Review on Non-Noble Metal Substrates for Surface-Enhanced Raman Scattering Detection." Chemosensors 11, no. 8 (August 1, 2023): 427. http://dx.doi.org/10.3390/chemosensors11080427.

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Surface-enhanced Raman scattering (SERS), a powerful spectroscopic technique owing to its abundant vibrational fingerprints, has been widely employed for the assay of analytes. It is generally considered that one of the critical factors determining the SERS performance is the property of the substrate materials. Apart from noble metal substrates, non-noble metal nanostructured materials, as emerging new substrates, have been extensively studied for SERS research by virtue of their superior biocompatibility, good chemical stability, outstanding selectivity, and unique physicochemical properties such as adjustable band structure and carrier concentration. Herein, in this review, we summarized the research on the analytical application of non-noble metal SERS substrates from three aspects. Firstly, we started with an introduction to the possible enhancement mechanism of non-noble metal substrates. Then, as a guideline for substrates design, several main types of materials, including carbon nanomaterials, transition metal dichalcogenides (TMDs), metal oxides, metal-organic frameworks (MOFs), transition metal carbides and nitrides (MXenes), and conjugated polymers were discussed. Finally, we especially emphasized their analytical application, such as the detection of pollutants and biomarkers. Moreover, the challenges and attractive research prospects of non-noble metal SERS substrates in practical application were proposed. This work may arouse more awareness of the practical application of the non-noble metal material-based SERS substrates, especially for bioanalysis.

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Lu, Song, Fengliu Lou, and Zhixin Yu. "Recent Progress in Two-Dimensional Materials for Electrocatalytic CO2 Reduction." Catalysts 12, no. 2 (February 17, 2022): 228. http://dx.doi.org/10.3390/catal12020228.

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Electrocatalytic CO2 reduction (ECR) is an attractive approach to convert atmospheric CO2 to value-added chemicals and fuels. However, this process is still hindered by sluggish CO2 reaction kinetics and the lack of efficient electrocatalysts. Therefore, new strategies for electrocatalyst design should be developed to solve these problems. Two-dimensional (2D) materials possess great potential in ECR because of their unique electronic and structural properties, excellent electrical conductivity, high atomic utilization and high specific surface area. In this review, we summarize the recent progress on 2D electrocatalysts applied in ECR. We first give a brief description of ECR fundamentals and then discuss in detail the development of different types of 2D electrocatalysts for ECR, including metal, graphene-based materials, transition metal dichalcogenides (TMDs), metal–organic frameworks (MOFs), metal oxide nanosheets and 2D materials incorporated with single atoms as single-atom catalysts (SACs). Metals, such as Ag, Cu, Au, Pt and Pd, graphene-based materials, metal-doped nitric carbide, TMDs and MOFs can mostly only produce CO with a Faradic efficiencies (FE) of 80~90%. Particularly, SACs can exhibit FEs of CO higher than 90%. Metal oxides and graphene-based materials can produce HCOOH, but the FEs are generally lower than that of CO. Only Cu-based materials can produce high carbon products such as C2H4 but they have low product selectivity. It was proposed that the design and synthesis of novel 2D materials for ECR should be based on thorough understanding of the reaction mechanism through combined theoretical prediction with experimental study, especially in situ characterization techniques. The gap between laboratory synthesis and large-scale production of 2D materials also needs to be closed for commercial applications.

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Suni, Ian Ivar. "Substrate Materials for Biomolecular Immobilization within Electrochemical Biosensors." Biosensors 11, no. 7 (July 15, 2021): 239. http://dx.doi.org/10.3390/bios11070239.

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Electrochemical biosensors have potential applications for agriculture, food safety, environmental monitoring, sports medicine, biomedicine, and other fields. One of the primary challenges in this field is the immobilization of biomolecular probes atop a solid substrate material with adequate stability, storage lifetime, and reproducibility. This review summarizes the current state of the art for covalent bonding of biomolecules onto solid substrate materials. Early research focused on the use of Au electrodes, with immobilization of biomolecules through ω-functionalized Au-thiol self-assembled monolayers (SAMs), but stability is usually inadequate due to the weak Au–S bond strength. Other noble substrates such as C, Pt, and Si have also been studied. While their nobility has the advantage of ensuring biocompatibility, it also has the disadvantage of making them relatively unreactive towards covalent bond formation. With the exception of Sn-doped In2O3 (indium tin oxide, ITO), most metal oxides are not electrically conductive enough for use within electrochemical biosensors. Recent research has focused on transition metal dichalcogenides (TMDs) such as MoS2 and on electrically conductive polymers such as polyaniline, polypyrrole, and polythiophene. In addition, the deposition of functionalized thin films from aryldiazonium cations has attracted significant attention as a substrate-independent method for biofunctionalization.

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Journal articles on the topic 'Transition Metal Oxides (TMOs)'

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