Articoli di riviste: "Nanostructures et nanocomposites"

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Doan, Mai Quan, Nguyen Ha Anh, Hoang Van Tuan, Nguyen Cong Tu, Nguyen Huu Lam, Nguyen Tien Khi, Vu Ngoc Phan, Pham Duc Thang e Anh-Tuan Le. "Improving SERS Sensing Efficiency and Catalytic Reduction Activity in Multifunctional Ternary Ag-TiO2-GO Nanostructures: Roles of Electron Transfer Process on Performance Enhancement". Adsorption Science & Technology 2021 (1 ottobre 2021): 1–13. http://dx.doi.org/10.1155/2021/1169599.

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Multifunctional nanocomposites have received great attention for years; electron transfer (ET) is considered as an explanatory mechanism for enhancement of performance of these nanostructures. The existence of this ET process has been proved in many studies using either experimental or computational approaches. In this study, a ternary nanocomposite system of Ag/TiO2/GO was prepared to evaluate the performance enhancement in two experimental models: a physical model (i.e., surface-enhanced Raman scattering (SERS) sensor) and a chemical one (i.e., catalytic reduction reaction). The metal/semiconductor heterojunction between Ag and TiO2, as well as Ti-O-C bonds, has allowed plasmonic hot electrons to be transferred in the internal structure of the material. An investigation on the role of Ag content on the SERS sensing and catalytic reduction efficiency of Ag/TiO2/GO was performed in both models. Interestingly, they all resulted in the same optimal Ag content of 50 wt%. It was then further discussed to provide a convincing evidence for the plasmon-induced electron transfer phenomena in the Ag/TiO2/GO nanostructure. These findings also suggest a pathway to design and develop high-performance, cost-effective, facile-preparation, and eco-friendly multifunctional nanostructures for detecting and removing contaminants in environment.

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Hammud, Hassan H., Ranjith Kumar Karnati, Nusaybah Alotaibi, Syed Ghazanfar Hussain e Thirumurugan Prakasam. "Cobalt–Carbon Nanoparticles with Silica Support for Uptake of Cationic and Anionic Dyes from Polluted Water". Molecules 26, n. 24 (10 dicembre 2021): 7489. http://dx.doi.org/10.3390/molecules26247489.

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Silica-supported hierarchical graphitic carbon sheltering cobalt nanoparticles Co-HGC@SiO2 (1) were prepared by pyrolysis at 850 °C of [Co(phen)(H2O)4]SO4·2H2O complex with silica in the presence of pyrene as a carbon source under nitrogen atmosphere. Nanocomposites (2) and (3) were obtained by acid treatment of (1) with HCl and HF acid, respectively. The nanocomposites showed rough hierarchical carbon microstructures over silica support decorated with irregular cobalt nanospheres and nanorods 50 to 200 nm in diameter. The nanoparticles consist of graphitic shells and cobalt cores. SEM, EDAX and TEM elemental mapping indicate a noticeable loss of cobalt in the case of (2) and loss of cobalt and silica in the case of (3) with an increase in porosity. Nanocomposite (3) showed the highest BET surface area 217.5 m2g−1. Raman spectrum shows defect D-band and graphitic G-band as expected in carbon nanostructures. PXRD reveals the presence of cobalt(0) nanoparticles. XPS indicates the presence of Co(II) oxides and the successful doping of nitrogen in the nanocomposites. Moreover, TEM elemental mapping provides information about the abundance of Si, Co, C, N and S elements in zones. Nanocomposite (1) showed maximum uptake capacity of 192.3 and 224.5 mg/g for crystal violet CV and methyl orange MO dyes, respectively. Nanocomposite (2) showed a capacity of 94.1 and 225.5 mg/g for CV and MO dyes, respectively. Nanocomposite (4) obtained after treatment of (1) with crystal violet proved successful adsorption of CV. Co-HGC (5) prepared without addition of silica has a capacity for CV equal to 192 mg/g, while it is 769.2 mg/g with MO. Electrostatics and π–π interactions of graphite and cobalt species in the nanocomposites with aromatic rings of cationic and anionic dyes are responsible for the adsorption. Yan et al. was the best model to describe column kinetics. The thomas column adsorption model showed that the maximum uptake capacity of (1) was 44.42 mg/g for CV and 32.62 mg/g for MO. for a column packed with 0.5 gm of (1) and dye concentration of 100 mg/L at a flow rate of 1 mL/min. The column was recycled three times with no noticeable clogging or degradation of nanocomposites. Thus, Co-HGC@SiO2 adsorbents can be used efficiently to treat water contaminated with cationic and anionic dyes.

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Granitzer, Petra, Klemens Rumpf, Roberto Gonzalez-Rodriguez e Jeffery Coffer. "Metal Filled Nanostructured Silicon a Platform to Interlink Magnetism and Optics". ECS Meeting Abstracts MA2023-02, n. 21 (22 dicembre 2023): 1285. http://dx.doi.org/10.1149/ma2023-02211285mtgabs.

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This presentation deals with the utilization of nanostructured silicon (porous silicon and silicon nanotubes) for deposition of various metals, especially magnetic ones, within the pores/tubes. The novel magnetic properties of the semiconducting/magnetic composites which arise due to the nanoscopic size of the used materials are investigated with respect to optical and magnetic on-chip applications. Porous silicon is fabricated by anodization of a silicon wafer in an aqueous hydrofluoric solution. The morphology of the porous structures depends on the doping density of the used wafer and on the applied current density as well as the electrolyte concentration. The ferromagnetic metals are deposited within the porous structures electrochemically in using the corresponding metal salt solution as electrolyte. A modification of the electrochemical parameters results in adjustable size and shape of the deposits. Ni and Co, both metals are electrodeposited within the nanostructured silicon in using aqueous NiSO4 and CoSO4 solutions by applying a current density between 10 and 20 mA/cm2 and a frequency between 0.05 and 0.2 Hz. One of our key topics is luminescent porous silicon loaded with magnetic metals to enhance the photoluminescence, with the final aim to influence/control the optical properties by a magnetic field. The metal deposits affect the optical properties but also give rise to specific magnetic behavior (1). Due to the metal filling of the porous silicon the photoluminescence is blue-shifted and furthermore an increase of the intensity is observed. The influence of the magnetic metal filling on the optical properties (photoluminescence, decay time) is discussed, and the magnetic characterization of the nanocomposites is presented. A further issue, the deposition of hard and soft magnetic materials within the nanostructures, aiming in the fabrication of arrays of permanent nanomagnets is presented (2). Here the investigation of the magnetic behavior of bi-metal nanostructures within nanostructured silicon with the aim to exploit the magnetic properties of both metals and gain control of the exchange coupling between the two metals especially with respect to their volume ratio is discussed. Furthermore, a variation of the structure size and the proximity of the metal deposits modify the exchange coupling and thus the energy product. Nanocomposite systems with an energy product as high as possible should be achieved to give rise to on-chip applications using permanent nanomagnets, especially arranged in arrays. (1) P. Granitzer, et al, Frontiers in Physics, 8 (2020) 121 (2) K. Rumpf, et.al, Phys. Stat. Sol. A, 217 (2020) 1901040

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El-Zoka, Ayman A. "(Invited) Making Nanostructured Composites Via Inner-Pore Electrodeposition into Nanoporous Metals". ECS Meeting Abstracts MA2023-02, n. 21 (22 dicembre 2023): 1281. http://dx.doi.org/10.1149/ma2023-02211281mtgabs.

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The selective removal of Ag from a solid solution of Ag-Au or Ag-Au-Pt yields a 3D bicontinuous, open-pore, nanoporous gold substrate (NPG), that is rich in the more noble metal(s)1 (Au and/or Pt). NPG has been successfully developed by the intelligent use of the conventionally-undesired dealloying corrosion. The excellent properties of NPG are attributed to the surface area-to-volume ratio, and high curvature of nanoligament surfaces2,3 . While a lot of recent research has been focusing on the structure/property relationships of NPG as a functional material in its own right4,5, the further use of NPG as a sophisticated template for fabricating complex nanostructured materials is worthy of attention. Previous work on atom probe tomography characterization of NPG6,7 showed the successful inner-pore electrodeposition of a fully compact Cu support, thus, opening the door to implementing that newly developed method to the creation of finely tuned nanostructures, using NPG as a template. Fabrication of functional nanostructures pertaining to the interests of the catalysis and mechanics communities will be demonstrated through the electrodeposition of Cu and Co on NPG. Key aspects that enable this unexpected complete infiltration of NPG layer will be highlighted including, a characteristic "subpotential" curvature-driven electrodeposition regime8. Insights on the associated electrodeposition mechanisms are gained through the pairing of electrochemical methods and high-resolution characterization techniques. Furthermore, recent advances in structural and chemical modifications that increase the complexity and tunability of NPG-based nanocomposites will be discussed for the first time. References Newman, R. C. 2.05 - Dealloying. in Shreir’s Corrosion (eds. Cottis, B. et al.) 801–809 (Elsevier, 2010). Zielasek, V. et al. Gold Catalysts: Nanoporous Gold Foams. Angewandte Chemie International Edition 45, 8241–8244 (2006). Xue, Y., Markmann, J., Duan, H., Weissmüller, J. & Huber, P. Switchable imbibition in nanoporous gold. Nature Communications 5, (2014). Wittstock, A., Wichmann, A., Biener, J. & Bäumer, M. Nanoporous gold: A new gold catalyst with tunable properties. Faraday Discuss (2011) doi:10.1039/c1fd00022e. Li, X. et al. Nanoporous-Gold-Based Hybrid Cantilevered Actuator Dealloyed and Driven by A Modified Rotary Triboelectric Nanogenerator. Sci Rep (2016) doi:10.1038/srep24092. El-Zoka, A. A., Langelier, B., Botton, G. A. & Newman, R. C. Enhanced analysis of nanoporous gold by atom probe tomography. Mater Charact 128, (2017). El-Zoka, A. A., Langelier, B., Korinek, A., Botton, G. A. & Newman, R. C. Nanoscale mechanism of the stabilization of nanoporous gold by alloyed platinum. Nanoscale 10, (2018). Lee, L., He, D., Carcea, A. G. & Newman, R. C. Exploring the reactivity and nanoscale morphology of de-alloyed layers. Corros Sci 49, 72–80 (2007).

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Rusu, Mihai M., Adriana Vulpoi, Isabelle Maurin, Liviu C. Cotet, Lucian C. Pop, Carmen I. Fort, Monica Baia, Lucian Baia e Ileana Florea. "Thermal Evolution of C–Fe–Bi Nanocomposite System: From Nanoparticle Formation to Heterogeneous Graphitization Stage". Microscopy and Microanalysis 28, n. 2 (1 marzo 2022): 317–29. http://dx.doi.org/10.1017/s1431927622000241.

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Carbon xerogel nanocomposites with integrated Bi and Fe particles (C–Bi–Fe) represent an interesting model of carbon nanostructures decorated with multifunctional nanoparticles (NPs) with applicability for electrochemical sensors and catalysts. The present study addresses the fundamental aspects of the catalyzed growth of nano-graphites in C–Bi–Fe systems, relevant in charge transport and thermo-chemical processes. The thermal evolution of a C–Bi–Fe xerogel is investigated using different pyrolysis treatments. At lower temperatures (~750°C), hybrid bismuth iron oxide (BFO) NPs are frequently observed, while graphitization manifests under more specific conditions such as higher temperatures (~1,050°C) and reduction yields. An in situ heating TEM experiment reveals graphitization activity between 800 and 900°C. NP motion is directly correlated with textural changes of the carbon support due to the catalyzed growth of graphitic nanoshells and nanofibers as confirmed by HR-TEM and electron tomography (ET) for the graphitized sample. An exponential growth model for the catalyst dynamics enables the approximation of activation energies as 0.68 and 0.29–0.34 eV during reduction and graphitization stages. The results suggest some similarities with the tip growth mechanism, while oxygen interference and the limited catalyst–feed gas interactions are considered as the main constraints to enhanced growth.

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Gan’shina, Elena A., Vladimir V. Garshin, Nikita S. Builov, Nikolay N. Zubar, Alexandr V. Sitnikov e Evelina P. Domashevskaya. "Investigation of the Magnetic Properties of Amorphous Multilayer Nanostructures [(CoFeB)60C40/SiO2]200 and [(CoFeB)34(SiO2)66/C]46 by the Transversal Kerr Effect". Kondensirovannye sredy i mezhfaznye granitsy = Condensed Matter and Interphases 22, n. 4 (15 dicembre 2020): 438–45. http://dx.doi.org/10.17308/kcmf.2020.22/3114.

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Magnetic properties in amorphous multilayer nanostructures [(CoFeB)60C40/SiO2]200 and [(CoFeB)34(SiO2)66/C]46 with different content of the CoFeB magnetic alloy in metal-composite layers and inverse location of non-metallic phases C and SiO2 in composite layers or in interlayers, were investigated by magneto-optical methods in the transversal Kerr effect (TKE) geometry.Using the spectral and field dependences of the transversal Kerr effect TKE, it has been established that in the samples of both magnetic multilayer nanostructures (MLNS) the magneto-optical response and magnetic order are determined by the phase composition of the composite layers.In samples of MLNS [(CoFeB)60C40/SiO2]200 with a post-percolation content of metal clusters in metal-composite layers, the maximum of absolute TKE values decrease by about 2.5 times compared with the initial amorphous Co40Fe40B20 alloy, while the field dependences of TKE in samples of this MLNS has features that are characteristic of soft ferromagnets.In samples of MLNS [(CoFeB)34(SiO2)66/C]46 with a pre-percolation content of metal clusters in the oxide SiO2–x matrix of metal-composite layers, the TKE spectral dependences fundamentally differed from the TKE of the initial amorphous Co40Fe40B20 alloy both in shape and sign. The field dependences of the TKE in the samples of this MLN were linear, characteristic of superparamagnets. References1. Neugebauer C. A. Resistivity of cermet filmscontaining oxides of silicon. Thin Solid Films. 1970;6(6):443–447. DOI: https://doi.org/10.1016/0040-6090(70)90005-22. Gittleman J. L., Goldstain Y., Bozowski S.Magnetic roperties of granular nikel films. PhysicalReview B. 1972;5(9): 3609–3621. DOI: https://doi.org/10.1103/physrevb.5.36093. Abeles B., Sheng P., Coutts M. D., Arie Y.Structural and electrical properties of granular metalfilms. Advances in Physics. 1975;24(3): 407–461. DOI:https://doi.org/10.1080/000187375001014314. Helman J. S., Abeles B. Tunneling of spinpolarizedelectrons and magnetoresistance in granularNi films. Physical Review Letters. 1976;37(21): 1429–1433. DOI: https://doi.org/10.1103/physrevlett.37.14295. Sheng P., Abeles B., Arie Y. Hopping conductivityin granular Metals. Physical Review Letters,1973;31(1):44–47. DOI: https://doi.org/10.1103/physrevlett.31.446. Domashevskaya E. P., Builov N. S., Terekhov V. A.,Barkov K. A., Sitnikov V. G. Electronic structure andphase composition of dielectric interlayers inmultilayer amorphous nanostructure [(CoFeB)60C40/SiO2]200. Physics of the Solid State. 2017;59(1): 168–173.DOI: https://doi.org/10.1134/S10637834170100617. Domashevskaya E. P., Builov N. S., Terekhov V. A.,Barkov K. I., Sitnikov V. G., Kalinin Y. E. Electronicstructure and phase composition of silicon oxide inthe metal-containing composite layers of a[(Co40Fe40B20)34(SiO2)66/C]46 multilayer amorphousnanostructure with carbon interlayers. InorganicMaterials. 2017;53(9): 930–936. DOI: https://doi.org/10.1134/S00201685170900608. Domashevskaya E. P., Builov N. S., Lukin A. N.,Sitnikov V. G. Investigation of interatomic interactionin multilayer nanostructures [(CoFeB)60C40/SiO2]200 and[(Co40Fe40B20)34(SiO2)66/C]46 with composite metalcontaininglayers by IR spectroscopy. InorganicMaterials. 2018;54(2): 153–159. DOI: https://doi.org/10.7868/s0002337x180200699. Domashevskaya E. P., Builov N. S., Ivkov S. A.,Guda A. A., Trigub A. L., Chukavin A. I. XPS and XASinvestigations of multilayer nanostructures based onthe amorphous CoFeB alloy. Journal of ElectronSpectroscopy and Related Phenomena. 2020;243:146979–146989. DOI: https://doi.org/10.1016/j.elspec.2020.14697910. Vonsovskii S. V. Magnetizm [Magnetism].Moscow: Nauka Publ.; 1971. 1032 p.11. Gan’shina E., Granovsky A., Gushin V.,Kuzmichev M., Podrugin P., Kravetz A., Shipil E. Opticaland magneto-optical spectra of magnetic granularalloys. Physica A: Statistical Mechanics and itsApplications. 1997;241(1-2): 45–51. DOI: https://doi.org/10.1016/s0378-4371(97)00057-512. Gan’shina E. A., Kim C. G., Kim C. O.,Kochneva M. Yu., Perov N. S., Sheverdyaeva P. M.Magnetostatic and magneto-optical properties of Cobasedamorphous ribbons. Journal of Magnetism andMagnetic Materials. 2002;239(1-3): 484–486. DOI:https://doi.org/10.1016/s0304-8853(01)00665-513. Gan’shina E. A., Vashuk M. V. Evolution of theoptical and magnetooptical properties of amorphousmetal-insulator nanocomposites. Journal ofExperimental and Theoretical Physics. 2004;98:1027–1036. DOI: https://doi.org/10.1134/1.176757114. Shalygina E. E., Kharlamova A. M., KurlyandskayaG. V., Svalov A. V. Exchange interaction in Co/Bi/Co thin-film systems with Bi interlayer. Journal ofMagnetism and Magnetic Materials. 2017;440: 136–139.DOI: https://doi.org/10.1016/j.jmmm.2016.12.14415. Gan’shina E., Garshin V., Perova N., Zykov G.,Aleshnikov A., Kalinin Yu., Sitnikov A. Magnetoopticalproperties of nanocomposites ferromagneticcarbon.Journal of Magnetism and Magnetic Materials.2019;470:135–138. DOI: https://doi.org/10.1016/j.jmmm.2017.11.03816. Buravtsova V. E., Ganshina E. A., Kirov S. A., et.al. Magnetooptical properties of layer-by-layerdeposited ferromagnet – dielectric nanocomposites.Materials Sciences and Applications. 2013;4(4): 16–23.DOI: http://dx.doi.org/10.4236/msa.2013.44A00317. Stognei O. V., Kalinin Yu. E., Zolotukhin I. V.,Sitnikov A. V., Wagner V., Ahlers F. J. Low temperaturebehaviour of the giant magnetoresistivity in CoFeB– SiOn granular composites. Journal of Physics:Condensed Matter. 2003;15(24): 4267–4772. DOI:https://doi.org/10.1088/0953-8984/15/24/32018. Stognei O. V., Sitnikov A. V. Anisotropy ofamorphous nanogranular composites CoNbTa-SiO nand CoFeB-SiOn. Physics Solid State. 2010;52: 2518–2526. DOI: https://doi.org/10.1134/S106378341012012719. Dunets O. V., Kalinin Y. E., Kashirin M. A. et al.Electrical and magnetic performance of multilayerstructures based on (Co40Fe40B20)33.9(SiO2)66.1 composite.Technical Physics. 2013;58: 1352–1357. DOI: https://doi.org/10.1134/S106378421309013220. Gridnev S. A., Kalinin Yu. E., Sitnikov A. V.,Stognei O. V. Nelineinye yavleniya v nano imikrogeterogennykh sistemakh [Nonlinear phenomenain nano and microheterogeneous systems]. Moscow:BINOM, Laboratoriya znanii Publ.; 2012. 352 p.21. Mørup S., Tronc E. Superparamagneticrelaxation of weakly interacting particles. PhysicalReview Letters. 1994;72(20): 3278–3285. DOI: https://doi.org/10.1103/PhysRevLett.72.327822. Coey J. M. D., Khalafalla D. Superparamagneticg-Fe2O3. Physica Status Solidi (a) 1972;11(1): 229–241.DOI: https://doi.org/10.1002/pssa.221011012523. Brown W. F. Thermal fluctuations of a singledomainparticle. Physical Review. 1963;130(5): 1677–1685. DOI: https://doi.org/10.1103/physrev.130.1677

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Ngene, Peter. "Interface Induced Fast Ion Conduction in Complex Hydride/Oxide Nanocomposites: Interplay between Hydride and Oxide Properties". ECS Meeting Abstracts MA2023-02, n. 5 (22 dicembre 2023): 886. http://dx.doi.org/10.1149/ma2023-025886mtgabs.

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Solid-state electrolytes are crucial for next generation batteries with high energy density, long lasting and improved safety. The compatibility of most solid electrolytes with metallic anodes such as Li and Na metals, and cathodes such as sulfur, makes them suitable for high-capacity batteries (e.g., Li-S). They also address the safety concerns of current batteries by eliminating the flammable organic solvents in liquid electrolytes and by preventing/limiting dendrite formation. The lithium and sodium containing complex metal hydrides (e.g., LiBH4, NaBH4, LiCB11H12) have recently gained attention as solid-state electrolyte. They show high ionic conductivities but only at elevated temperatures (typically above 110 °C). Extending the high ionic conductivities to ambient temperatures is pivotal to the application of this fascinating class of solid electrolytes [1]. In this contribution, we will use LiBH4 and NaBH4 as examples to show that the ionic conductivities of complex hydrides can be greatly enhanced through interface effects resulting from the formation of nanocomposites with metal oxides. This strategy can lead to several orders of magnitude increase in the room temperature ionic conductivity [2]. Using DSC, DRIFT, solid-state NMR, and XRS (Xray Raman scattering), I will discuss how nanocomposite formation and presence of interfaces modifies either the phase stability, the defect concentration and/or leads to the formation of tertiary phase, and thereby increase profoundly the ion mobility of the complex hydrides. Systematic studies with different oxide nanoscaffolds and surface modified metal oxides, reveal that these effects can be optimized by tuning/engineering the nanostructure and interfaces in the nanocomposites. [3-4]. We will show that the effects also depend on a complex interplay between the stability of the metal hydride and surface properties of the metal oxide. Finally, the performance of some of the nanocomposite electrolytes in all-solid-state batteries, will be highlighted [5] References [1] L.M de Kort, P. Ngene et al. J. Journal of Alloys and Compounds 901 (2022) 163474 [2] D. Blanchard et al., Advanced Functional Material. 25 (2015), 182. [3] P. Ngene et al. Physical Chemistry Chemical Physics 21 (40), 22456-22466 [4] L.M de Kort, P. Ngene et al. Journal of Materials Chemistry A 8.39 (2020): 20687-20697 [5] D. Blanchard et al, J. Electrochem. Soc. (2016).

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Yang, Bao Juan, Rui Xia, Su Bin Jiang e Mei Zhen Gao. "SnSe/Cu<sub>2</sub>SnSe<sub>3</sub> Heterojunction Structure with High Initial Coulombic Efficiency for Lithium-Ion Battery Anodes". Key Engineering Materials 905 (4 gennaio 2022): 135–41. http://dx.doi.org/10.4028/www.scientific.net/kem.905.135.

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Due to high theoretical specific capacity and abundant reserves, tin selenide-based materials have received tremendous attentions in the fields of lithium-ion batteries. Nevertheless, the huge volume changes during insertion/de-intercalation processes deteriorate the Coulombic Efficiency greatly. In order to solve it, the researchers have made great efforts by means of controlling nanoparticles granularity, carbon coating, ion doping et al. In this study, SnSe/Cu2SnSe3 heterojunction nanocomposites were synthesized by solvo-thermal method. The resulting SnSe/Cu2SnSe3 is a three-dimensional flower-like hierarchical nanostructure composed of nanoscale thin lamellae of a thickness of 8-12 nm. The unique nanostructure could shorten the diffusion path of lithium ions and expedite charge transfer, and therefore enhance the reaction kinetics. Compared with SnSe, the initial Coulombic efficiency of SnSe/Cu2SnSe3 is raised from 59% to 90% as the anode material of lithium-ion batteries.

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Urper, Osman, Prabin Kharel, Nivedhitha Jothinarayanan, Karoline Krogstad, Lars Eric-Roseng, Miina Saebo, Walter Aker e Kaiying Wang. "Eco-Friendly TiO₂ and ZnO Biocar Nanocomposites: Transforming Water Decontamination and Bacteria Inactivation". ECS Meeting Abstracts MA2023-02, n. 47 (22 dicembre 2023): 2292. http://dx.doi.org/10.1149/ma2023-02472292mtgabs.

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Water pollution ranging from harmful chemical substances to pathogenic bacteria is a growing problem from industry to society as a whole[1-2].There is a need to find new, cost-effective sustainable materials with high efficacy to clean up water and to protect the environment. Biocarbon (BC), a material with high specific surface area and large porosity, has some potential for removing water pollutants, but it also has many limitations. However, biocarbon-based composites can be tailored and may have a greater potential for removing contaminants in water. ZnO biochar and TiO2 biochar nanocomposites have been shown to effectively remove harmful chemical substances, such as industrial dyes, and additionally kill potential pathogenic bacteria[2–8]. In this project, we combined TiO2 and ZnO with biochar to create an active nanocomposite surface to see if this could be a cost-effective method to deactivate bacteria and degrade specific dyes. We present the fabrication and examination of TiO2/biochar (BC) and ZnO/BC composite photocatalysts, synthesized via hydrolysis technique. These catalysts were designed for the purpose of methyl orange (MO) degradation and bacterial strain inactivation. A comprehensive assessment of these catalysts was carried out using a number of sophisticated methods, including scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and UV-Vis spectrophotometry for evaluation of degradation. Moreover, the direct contact method was used for antibacterial analysis. Our findings underline the exceptional properties of these composites for water decontamination and antibacterial efficacy. The nanocomposites showed remarkable photocatalytic performance in MO removal from wastewater, achieving a superior removal efficiency of 92%, as shown in Figure 1. This can be attributed to their outstanding electron transfer efficacy. In addition, the TiO2/BC and ZnO/BC nanocomposites manifested robust antibacterial properties, and they showed an antibacterial effectiveness of 85% against Escherichia coli (E. coli) (Table 1). This research highlights the promising potential of TiO2/BC and ZnO/BC nanocomposites as eco-friendly and multifaceted materials, suggesting a wide range of potential applications in water purification and antibacterial activity. Acknowledgments: The authors acknowledge the research grants from project # 6000237-13 Figure: Figure 1. Photocatalytic degradation of MO (initial concentration; 20 mg/L) under solar light irradiation, a) Pure BC and TiO2, and composite TiO2/BC catalysts, b) Pure BC and ZnO, and ZnO/BC catalysts. Table: Table 1. Antimicrobial efficiency of 5 different catalysts against E. coli. References [1] A. S. Eltaweil, I. M. Mamdouh, E. M. Abd El-Monaem, and G. M. El-Subruiti, “Highly Efficient Removal for Methylene Blue and Cu2+onto UiO-66 Metal-Organic Framework/Carboxylated Graphene Oxide-Incorporated Sodium Alginate Beads,” ACS Omega, 2021, doi: 10.1021/acsomega.1c03479. [2] J. Hidalgo-Jimenez et al., “Phase transformations, vacancy formation and variations of optical and photocatalytic properties in TiO2-ZnO composites by high-pressure torsion,” Int J Plast, vol. 124, pp. 170–185, Jan. 2020, doi: 10.1016/j.ijplas.2019.08.010. [3] A. S. Eltaweil, A. M. Abdelfatah, M. Hosny, and M. Fawzy, “Novel Biogenic Synthesis of a Ag@Biochar Nanocomposite as an Antimicrobial Agent and Photocatalyst for Methylene Blue Degradation,” ACS Omega, vol. 7, no. 9, pp. 8046–8059, Mar. 2022, doi: 10.1021/acsomega.1c07209. [4] S. Riaz and S. J. Park, “An overview of TiO2-based photocatalytic membrane reactors for water and wastewater treatments,” Journal of Industrial and Engineering Chemistry, vol. 84. Korean Society of Industrial Engineering Chemistry, pp. 23–41, Apr. 25, 2020. doi: 10.1016/j.jiec.2019.12.021. [5] L. Lu, R. Shan, Y. Shi, S. Wang, and H. Yuan, “A novel TiO2/biochar composite catalysts for photocatalytic degradation of methyl orange,” Chemosphere, vol. 222, pp. 391–398, May 2019, doi: 10.1016/j.chemosphere.2019.01.132. [6] R. Zha, R. Nadimicherla, and X. Guo, “Ultraviolet photocatalytic degradation of methyl orange by nanostructured TiO2/ZnO heterojunctions,” J Mater Chem A Mater, vol. 3, no. 12, pp. 6565–6574, Mar. 2015, doi: 10.1039/c5ta00764j. [7] J. Liu et al., “Preparation, environmental application and prospect of biochar-supported metal nanoparticles: A review,” Journal of Hazardous Materials, vol. 388. Elsevier B.V., Apr. 15, 2020. doi: 10.1016/j.jhazmat.2020.122026. [8] J. Liu et al., “Preparation, environmental application and prospect of biochar-supported metal nanoparticles: A review,” Journal of Hazardous Materials, vol. 388. Elsevier B.V., Apr. 15, 2020. doi: 10.1016/j.jhazmat.2020.122026. Figure 1

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Steier, Katharina, Peter James Kelly e Justyna Kulczyk-Malecka. "Vanadium-Doped Ni/YSZ Anode Functional Layers for Solid Oxide Fuel Cells Produced via Magnetron Sputtering". ECS Meeting Abstracts MA2023-01, n. 54 (28 agosto 2023): 76. http://dx.doi.org/10.1149/ma2023-015476mtgabs.

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The electrode performance of solid oxide fuel cells (SOFC) strongly depends on its microstructural characteristics, such as the porosity, percolated paths of ionically and electronically conductive phases and in particular, the grain size1. Deploying alternative manufacturing techniques that deposit nanostructured materials results in finer particle sizes and thus, increases the quantity of triple-phase boundaries. For that reason, the magnetron sputtering technique, which offers elemental distribution at the nanoscale, high deposition rates, reproducibility, scalability and excellent uniformity over large-area substrates has been chosen as the deposition method to fabricate anode functional layers (AFLs) for SOFCs. Nanostructured NiO-YSZ thin films have been previously produced by reactive pulsed DC magnetron co-sputtering of metallic targets of zirconium-yttrium and nickel, defining the optimal deposition parameters to create state-of the-art AFLs. Former studies reported limitations of the process control during reactive magnetron sputtering, regarding the film’s composition 1,2. Since the composition strongly relies on the amount of reactive gas, i.e., oxygen, present during deposition, a feedback control system is required to prevent oxygen built-up leading to target poisoning and lower deposition rates. Herein, we present a reactive feedback control system, that manages quantities of oxygen introduced to the sputtering chamber during deposition based on the oxygen partial pressure. This facilitates stable operation conditions, prevents target poisoning, and maintains the coating characteristics, i.e., its microstructure and desired composition when varying process parameters, such as the deposition pressure, target-substrate distance, or the deposition angle. Based on recent studies 3–5, the future of oxide-based anode materials for SOFCs will greatly focus on reducing the Ni catalyst content through alternative non-precious metal doping and increasing the cell performance by tailoring the microstructure of the AFL. This would allow Ni coarsening to be mitigated and maintain the nanostructure over the lifetime of the cell. Therefore, in this study complex transition metal oxides, such as vanadium, tantalum or manganese oxides, were doped into SOFC anodes to study their influence on the structural and morphological properties of magnetron sputtered AFL. The effect of dopant concentration on the properties of Ni-YSZ films in as-deposited, pre-annealed and reduced state was analysed using SEM, EDS, XRD and XPS. To characterise the electrochemical performance of the deposited films, polarisation curves were obtained from SOFC single stack assemblies under hydrogen and air flows for anode and cathode, respectively, at operating temperatures of 750, 800 and 850 ℃. References Lim, Y., Lee, H., Hong, S. & Kim, Y. B. Co-sputtered nanocomposite nickel cermet anode for high-performance low-temperature solid oxide fuel cells. J. Power Sources 412, 160–169 (2019). Ionov, I. V. et al. Reactive co-sputter deposition of nanostructured cermet anodes for solid oxide fuel cells. Jpn. J. Appl. Phys. 57, 30–34 (2018). Atkinson, A. et al. Advanced anodes for high-temperature fuel cells. Nat. Mater. 3, 17–27 (2004). Van Overmeere, Q. & Ramanathan, S. Thin film fuel cells with vanadium oxide anodes: Strain and stoichiometry effects. Electrochim. Acta 150, 83–88 (2014). Garcia-Garcia, F. J., Beltran, A. M., Yubero, F., Gonzalez-Elipe, A. R. & Lambert, R. M. High performance novel gadolinium doped ceria / yttria stabilized zirconia / nickel layered and hybrid thin film anodes for application in solid oxide fuel cells. J. Power Sources 363, 251–259 (2017). Figure 1

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Nuftolla, Aidarbek, Aizhan Rakhmanova, Baktiyar Soltabayev e Almagul Mentbayeva. "ZnO Intercalated PVA-PEDOT:PSS Composite Nanofiber for Detection of Ammonia Gases". ECS Meeting Abstracts MA2023-01, n. 53 (28 agosto 2023): 2654. http://dx.doi.org/10.1149/ma2023-01532654mtgabs.

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Keywords: Ammonia, Electrospinning, and Zinc Oxide The matter of air pollution has dramatically risen the worldwide concern on detecting of hazardous gases present in the atmosphere because they are highly detrimental to human health [4,5]. Additionally, the detection and monitoring of such harmful gases is necessary for process control in the industry as well as the general safety of the environment. Zinc oxide (ZnO) is an n-type semiconductor with a wide direct bandgap width (3.37 eV), high excitation binding energy (60meV), high electron mobility, thermal stability, and excellent electrical properties [1]. Other promising materials for gas-sensing applications encompass single elements, silicon and tellurium-based materials and organic semiconductors. The sensing materials that are of intense research interest are conducting polymers such as polyaniline (PANI), polypyrrole (PPy) and poly(3,4-thylenedioxythiophene) (PEDOT) used in the fabrication of polymer-based gas sensors [2]. Its capability to work at low operating temperatures while maintaining high sensitivity leads to the synergistic effect when in combination with metal oxides to produce high-performance gas sensors. They are very appealing in terms of energy saving as they do not need an additional source of heat, consequently reducing the operating cost, simplifying the fabrication process, and extending the lifespan of the device [3]. In this work, ZnO intercalated PVA-PEDOT:PSS composite nanofiber as a sensing layer was prepared by electrospinning method. This material was characterized both morphologically and structurally by X-ray diffraction analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy and thermogravimetric analysis. The results from TEM and SEM show well distribution of ZnO particles in the polymer matrix. The gas measurement results reveal that the fabricated ZnO loaded PVA-PEDOT:PSS composite sensor exhibits excellent gas response (63%) to ammonia gas in 100 ppm gas concentration at 120 °C. Acknowledgment This research was supported by the research grant 021220CRP0122 “Development of highly sensitive MOS based nano-film gas sensors” from Nazarbayev University. References S. Bhati, M. Hojamberdiev, and M. Kumar, “Enhanced sensing performance of ZnO nanostructures-based gas sensors: A Review,” Energy Reports, vol. 6, pp. 46–62, 2020. Yan, Y. et al. (2020) “Conducting polymer-inorganic nanocomposite-based Gas Sensors: A Review,” Science and Technology of Advanced Materials, 21(1), pp. 768–786. Zhang, J. et al. (2015) “Nanostructured materials for room-temperature gas sensors,” Advanced Materials, 28(5), pp. 795–831. C. Eze, E. Schaffner, E. Fischer, T. Schikowski, M. Adam, M. Imboden, M. Tsai, D. Carballo, A. von Eckardstein, N. Künzli, C. Schindler, and N. Probst-Hensch, “Long-term air pollution exposure and diabetes in a population-based Swiss cohort,” Environment International, vol. 70, pp. 95–105, 2014. C. Shim, J. Han, D. K. Henze, M. W. Shephard, L. Zhu, N. Moon, S. K. Kharol, E. Dammers, and K. Cady-Pereira, “Impact of NH3 emissions on particulate matter pollution in South Korea: A case study of the seoul metropolitan area,” Atmosphere, vol. 13, no. 8, p. 1227, 2022. Figure 1

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El Diwany, Farah, Taher Al Najjar, Basant Ali, Nageh K. Allam e Ehab El Sawy. "(Invited) Fullerene and Fullerene Nanocomposites for an Enhanced All-Vanadium Redox Flow Battery". ECS Meeting Abstracts MA2022-01, n. 11 (7 luglio 2022): 819. http://dx.doi.org/10.1149/ma2022-0111819mtgabs.

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The dependence on fossil fuels to meet the world energy demand caused several social, economical, and environmental problems. An immediate switch to sustainable, clean, and renewable sources of energy is a necessity. To achieve this switch, developing efficient technologies to convert renewable energy sources into electricity is a necessity but not enough due to the intermittent behavior of renewable sources. The incorporation of energy storage systems as regulators allows for the sustainable integration of renewable energy resources into the electrical grid. Vanadium redox flow batteries (VRFBs) are the most promising candidates of the currently available energy storage technologies, as they have an unlimited capacity (theoretically) and design flexibility. Enhancing the kinetics of the VRFBs electrochemical reactions will enhance their energy efficiency, and hence decrease the kWh cost of VRFBs. Currently, carbon-based electrodes are employed due to their suitable stability and conductivity, but with no treatment, they suffer from sluggish kinetics, hydrophobicity, and parasitic reactions catalyzation.1 Modifying these carbon-based electrodes with carbon nanostructures2 and metal oxides(MOx)3 was found to enhance the kinetics at the VRFB electrodes. Even though fullerenes have very unique structural and chemical properties they were rarely explored for the VRFBs application.4 In this work, fullerene C76 showed superior electrocatalytic activity towards VO2+/VO2 + redox reaction in G1 and G3 VRFBs and eliminated the necessity for thermal treatment of the carbon cloth support while inhibiting the chlorine evolution in G3 VRFB. A composite of C76 and hydrated WOx that reduces the fullerene content to half further inhibited the chance for chlorine evolution while maintaining the catalytic activity. References: Y. Gao et al., Carbon, 148, 9–15 (2019). D. O. Opar, R. Nankya, J. Lee, and H. Jung, Electrochimica Acta, 330, 135276 (2020). M. Faraji, R. Khalilzadeh Soltanahmadi, S. Seyfi, B. Mostafavi Bavani, and H. Mohammadzadeh Aydisheh, J Solid State Electrochem, 24, 2315–2324 (2020). F. A. E. Diwany, B. A. Ali, E. N. E. Sawy, and N. K. Allam, Chem. Commun., 56, 7569–7572 (2020).

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Akbar, Said Ali. "Sensor Gas Amonia Berbasis Polimer Konduktif Polianilina: Sebuah Review". QUIMICA: Jurnal Kimia Sains dan Terapan 3, n. 2 (2 febbraio 2022): 1–8. http://dx.doi.org/10.33059/jq.v3i2.4678.

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Artikel review ini memberikan informasi tentang aplikasi polianilina (PANI) dan kompositnya sebagai sensor gas berbahaya khususnya amonia (NH3). Kajian yang dibahas pada artikel ini meliputi sifat gas NH3, material komposit, kinerja sensor, serta limit deteksi. Tinjauan sensor gas amonia berbasis polimer konduktif polianilina secara menyeluruh diambil dari referensi sepuluh tahun terakhir. Sebagai contoh, komposit polianilina dengan turunan karbon seperti reduced Graphene Oxide (rGO) dan Carbon Nanotube menunjukkan limit deteksi hingga 46 ppb dengan waktu pemulihan hanya 75 detik. Selain itu, komposit PANI dengan logam seperti Ag, Sr dan sebagainya, menunjukkan limit deteksi yang lebih besar yaitu 1 ppm, namun terdapat keunggulan dimana waktu pemulihan hanya 4 deti. Oleh sebab itu, polimer konduktif polianilina menjadi material yang sangat menjanjikan untuk mendeteksi keberadaan gas NH3. Terakhir, mekanisme penginderaan gas amonia terhadap material PANI juga dibahas pada tulisan ini. Referensi: [1] M. Insausti, R. Timmis, R. Kinnersley, and M. C. Rufino, “Advances in sensing ammonia from agricultural sources,” Science of the Total Environment, vol. 706. 2020. doi: 10.1016/j.scitotenv.2019.135124. [2] H. Shen et al., “Intense Warming Will Significantly Increase Cropland Ammonia Volatilization Threatening Food Security and Ecosystem Health,” One Earth, vol. 3, no. 1, 2020, doi: 10.1016/j.oneear.2020.06.015. [3] W. Wu, B. Wei, G. Li, L. Chen, J. Wang, and J. Ma, “Study on ammonia gas high temperature corrosion coupled erosion wear characteristics of circulating fluidized bed boiler,” Engineering Failure Analysis, vol. 132, p. 105896, 2022, doi: https://doi.org/10.1016/j.engfailanal.2021.105896. [4] X. Huang et al., “Reduced graphene oxide–polyaniline hybrid: Preparation, characterization and its applications for ammonia gas sensing,” Journal of Materials Chemistry, vol. 22, no. 42, pp. 22488–22495, 2012, doi: 10.1039/C2JM34340A. [5] T. Jiang, P. Wan, Z. Ren, and S. Yan, “Anisotropic Polyaniline/SWCNT Composite Films Prepared by in Situ Electropolymerization on Highly Oriented Polyethylene for High-Efficiency Ammonia Sensor,” ACS Applied Materials & Interfaces, vol. 11, no. 41, pp. 38169–38176, Oct. 2019, doi: 10.1021/acsami.9b13336. [6] H. Bai and G. Shi, “Gas sensors based on conducting polymers,” Sensors, vol. 7, no. 3. 2007. doi: 10.3390/s7030267. [7] D. Kwak, Y. Lei, and R. Maric, “Ammonia gas sensors: A comprehensive review,” Talanta, vol. 204. 2019. doi: 10.1016/j.talanta.2019.06.034. [8] M. Eising, C. E. Cava, R. V. Salvatierra, A. J. G. Zarbin, and L. S. Roman, “Doping effect on self-assembled films of polyaniline and carbon nanotube applied as ammonia gas sensor,” Sensors and Actuators, B: Chemical, vol. 245, pp. 25–33, 2017, doi: 10.1016/j.snb.2017.01.132. [9] M. P. Diana, W. S. Roekmijati, and W. U. Suyud, “Why it is often underestimated: Historical Study of Ammonia Gas Exposure Impacts towards Human Health,” in E3S Web of Conferences, 2018, vol. 73. doi: 10.1051/e3sconf/20187306003. [10] R. T. Xu et al., “Half-Century Ammonia Emissions From Agricultural Systems in Southern Asia: Magnitude, Spatiotemporal Patterns, and Implications for Human Health,” GeoHealth, vol. 2, no. 1, 2018, doi: 10.1002/2017GH000098. [11] S. A. Akbar, A. Mardhiah, N. Saidi, and D. Lelifajri, “The effect of graphite composition on polyaniline film performance for formalin gas sensor,” Bulletin of the Chemical Society of Ethiopia, vol. 34, no. 3, 2021, doi: 10.4314/bcse.v34i3.14. [12] X. Wang, L. Gong, D. Zhang, X. Fan, Y. Jin, and L. Guo, “Room temperature ammonia gas sensor based on polyaniline/copper ferrite binary nanocomposites,” Sensors and Actuators B: Chemical, vol. 322, p. 128615, 2020, doi: https://doi.org/10.1016/j.snb.2020.128615. [13] L. Wang et al., “Enhanced Sensitivity and Stability of Room-Temperature NH3 Sensors Using Core–Shell CeO2 Nanoparticles@Cross-linked PANI with p–n Heterojunctions,” ACS Applied Materials &Interfaces, vol. 6, no. 16, pp. 14131–14140, Aug. 2014, doi: 10.1021/am503286h. [14] Y. Guo et al., “Hierarchical graphene–polyaniline nanocomposite films for high-performance flexible electronic gas sensors,” Nanoscale, vol. 8, no. 23, pp. 12073–12080, 2016, doi: 10.1039/C6NR02540D. [15] M. Eising, C. E. Cava, R. V. Salvatierra, A. J. G. Zarbin, and L. S. Roman, “Doping effect on self-assembled films of polyaniline and carbon nanotube applied as ammonia gas sensor,” Sensors and Actuators B: Chemical, vol. 245, pp. 25–33, 2017, doi: https://doi.org/10.1016/j.snb.2017.01.132. [16] S. Bai et al., “Transparent conducting films of hierarchically nanostructured polyaniline networks on flexible substrates for high-performance gas sensors,” Small, vol. 11, no. 3, 2015, doi: 10.1002/smll.201401865. [17] Z. Wu et al., “Enhanced sensitivity of ammonia sensor using graphene/polyaniline nanocomposite,” Sensors and Actuators, B: Chemical, vol. 178, 2013, doi: 10.1016/j.snb.2013.01.014. [18] N. R. Tanguy, B. Wiltshire, M. Arjmand, M. H. Zarifi, and N. Yan, “Highly Sensitive and Contactless Ammonia Detection Based on Nanocomposites of Phosphate-Functionalized Reduced Graphene Oxide/Polyaniline Immobilized on Microstrip Resonators,” ACS Applied Materials and Interfaces, vol. 12, no. 8, 2020, doi: 10.1021/acsami.9b21063. [19] D. Maity and R. T. R. Kumar, “Polyaniline Anchored MWCNTs on Fabric for High Performance Wearable Ammonia Sensor,” ACS Sensors, vol. 3, no. 9, 2018, doi: 10.1021/acssensors.8b00589. [20] J. Ma et al., “Multi-walled carbon nanotubes/polyaniline on the ethylenediamine modified polyethylene terephthalate fibers for a flexible room temperature ammonia gas sensor with high responses,” Sensors and Actuators, B: Chemical, vol. 334, May 2021, doi: 10.1016/j.snb.2021.129677. [21] A. Javadian-Saraf, E. Hosseini, B. D. Wiltshire, M. H. Zarifi, and M. Arjmand, “Graphene oxide/polyaniline-based microwave split-ring resonator: A versatile platform towards ammonia sensing,” Journal of Hazardous Materials, vol. 418, Sep. 2021, doi: 10.1016/j.jhazmat.2021.126283. [22] A. Liu et al., “The gas sensor utilizing polyaniline/ MoS2 nanosheets/ SnO2 nanotubes for the room temperature detection of ammonia,” Sensors and Actuators, B: Chemical, vol. 332, Apr. 2021, doi: 10.1016/j.snb.2021.129444. [23] Q. Feng, H. Zhang, Y. Shi, X. Yu, and G. Lan, “Preparation and gas sensing properties of PANI/SnO2 hybrid material,” Polymers, vol. 13, no. 9, May 2021, doi: 10.3390/polym13091360. [24] S. Benhouhou, A. Mekki, M. Ayat, and N. Gabouze, “Facile Preparation of PANI-Sr Composite Flexible Thin Film for Ammonia Sensing at Very Low Concentration,” Macromolecular Research, vol. 29, no. 4, pp. 267–279, Apr. 2021, doi: 10.1007/s13233-021-9034-3. [25] X. Wang et al., “In situ polymerized polyaniline/MXene (V2C) as building blocks of supercapacitor and ammonia sensor self-powered by electromagnetic-triboelectric hybrid generator,” Nano Energy, vol. 88, Oct. 2021, doi: 10.1016/j.nanoen.2021.106242. [26] J. Chang et al., “Polyaniline-Reduced Graphene Oxide Nanosheets for Room Temperature NH3Detection,” ACS Applied Nano Materials, vol. 4, no. 5, pp. 5263–5272, May 2021, doi: 10.1021/acsanm.1c00633. [27] S. Matindoust, A. Farzi, M. Baghaei Nejad, M. H. Shahrokh Abadi, Z. Zou, and L. R. Zheng, “Ammonia gas sensor based on flexible polyaniline films for rapid detection of spoilage in protein-rich foods,” Journal of Materials Science: Materials in Electronics, vol. 28, no. 11, 2017, doi: 10.1007/s10854-017-6471-z. [28] J. Cai, C. Zhang, A. Khan, C. Liang, and W. di Li, “Highly transparent and flexible polyaniline mesh sensor for chemiresistive sensing of ammonia gas,” RSC Advances, vol. 8, no. 10, pp. 5312–5320, 2018, doi: 10.1039/c7ra13516e. [29] T. Syrový et al., “Gravure-printed ammonia sensor based on organic polyaniline colloids,” Sensors and Actuators, B: Chemical, vol. 225, pp. 510–516, Mar. 2016, doi: 10.1016/j.snb.2015.11.062.

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de Jesus, Jemmyson. "Nanostructured Materials as an Analytical Strategy to Unravel and Treat Human Diseases: The Practical Challenges Behind the Theory". Brazilian Journal of Analytical Chemistry 9, n. 36 (5 luglio 2022): 10–13. http://dx.doi.org/10.30744/brjac.2179-3425.letter.jrdejesus.n36.

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In recent years, the world has witnessed important progress in the field of nanotechnology, which has strongly impacted the various fields of science and industry, creating new applications in electronics, medicine, and energy storage. In this sense, several nanoscale materials with different compositions have been produced and reported in the literature. Nanomaterials can be classified according to their composition. For example, silicon dioxide (SiO2), quantum dots (QDs), carbon dots (CDs), and nanoparticles (metallic and non-metallic), among others, have been widely synthetized and applied in several area. In nanomedicine, more specifically, the literature shows that nanoscale materials have shown numerous advantages, including unravelling and/or treating human diseases. In theory, due to unique optical properties, relative stability, high brightness, high quantum yield, biocompatibility, and biodegradability, some nanomaterials can be used as promising tools to assist in the generation of bioimages, diagnosis, and treatments of human diseases. To guarantee specific interactions between nanoparticles and cells, the adsorptive properties of nanomaterials are altered by the selective functionalization of the particles, allowing different clinical applications. For example, Zhang et al. reported a new method for cancer identification called multiplexed nanomaterial-assisted laser desorption/ionization for cancer identification (MNALCI). In this study, Au/SiO2 core/shell nanoparticles were used as the nanostructured material. The MNALCI was applied to 1,183 subjects, including 233 healthy controls and 950 patients with different types of cancer from two independent cohorts. MNALCI demonstrated a sensitivity of 93% to 91% to distinguish cancers from healthy controls. Satisfactory accuracy and minimal sample consumption make MNALCI a promising solution for non-invasive cancer diagnosis. In another study, magnetic NPs (MNPs), combined with oligomer-specific antibodies targeting neurotoxic beta-amyloid oligomers (AβOs), were evaluated in vitro and in vivo for imaging neurodegenerative diseases. Furthermore, nanocomposites (natural or synthetic) have been used as nanocarriers to carry out controlled drug delivery to target regions and even for reconstitution of necrotic tissues (tissue engineering).

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Vrushabendrakumar, Damini, Kazi Alam, Narendra Chaulagain, Navneet Kumar e Karthik Shankar. "Visible Light Driven CO₂ Photoreduction Using TiO₂ Nanotube Arrays Embedded with Low Bandgap Carbon Nitride Nanoparticles". ECS Meeting Abstracts MA2023-02, n. 9 (22 dicembre 2023): 1033. http://dx.doi.org/10.1149/ma2023-0291033mtgabs.

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The extraordinary thermal and photochemical stability, superior charge transport, and tunable band positions of graphitic carbon nitride (g-CN), which is constituted of elements that are plentiful on Earth, renders g-CN an important semiconductor photocatalyst for heterogeneous catalysis [1,2]. Despite these advantages, carbon nitride-based semiconductors do not function effectively as freestanding photocatalysts or photoelectrodes due to a rapid carrier recombination rate and a slightly wide bandgap that only enables them to capture blue and UV photons [3,4]. Anodically formed TiO2 nanotube arrays (TNTAs) are semiconducting wide bandgap scaffolds with excellent photocatalytic properties due to the intrinsic orthogonalization of charge generation/transport and charge transfer processes. Herein, we use a novel in situ electrophoretic anodization to embed low bandgap carbon nitride nanoparticles (CNNPs) in the walls of titania nanotubes. The likelihood of the CNNPs leaching off the TNTA photoanode during photoelectrochemical processes was eliminated by encapsulating CN inside a TiO2 matrix. CNNPs were formed by the thermal condensation polymerization of carbon nitride utilizing citric acid and urea as the precursors, and exhibited some unusual properties, including a lower bandgap of 2.1 eV, a highly redshifted fluorescence emission maximum at 2.35 eV, surface carboxylate groups, and the emergence of unique structural characteristics corresponding to amorphous yet graphitic carbon [5]. In contrast to bulk g-CN, which has a C:N ratio of 0.75, the CNNPs possessed an elevated C:N ratio as high as 1.87 at the surface. The additional carbon was found to be both amorphous and graphitic, although the structural characteristics of g-CN were mostly unaffected, as validated by diffractometric and spectroscopic data. Even in the absence of a sacrificial agent, the CNNP@TNT nanocomposite demonstrated enhanced performance in sunlight-driven CO2 photoreduction. When compared to the freestanding TNT photocatalyst, the CO yield of photoreduction for the CN@TNT hybrid was more than three times higher. UV-filtered illumination of the CNNP@TNT heterojunction photocatalyst generated appreciable quantities of methane and CO (3.41 and 8.78 μmolg–1h–1 respectively). In situ electrophoretic anodization is an innovative approach to incorporate semiconductor quantum dots into TiO2 nanotubes or other electrochemically grown nanostructures. REFERENCES 1. Kessler, F. K. et al., Nature Reviews Materials (2017) 2 (6), 1. 2. Chaulagain, N. et al., ACS Applied Materials & Interfaces (2022) 14 (21), pp. 24309-24320. 3. Kumar, P. et al., Advanced Optical Materials (2020) 8 (4), Art. No. 1901275. 4. Fu, J. et al., Advanced Energy Materials (2018) 8 (3), Art. No. 1701503. 5. Alam, K.M. et al., Chemical Engineering Journal (2023) 456, Art. No. 141067.

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Kumta, Prashant, Oleg Velikokhatnyi e Ramalinga Kuruba. "(Invited) From Lithiated Transition Metal Oxide to Silicon and Lithium-Sulfur Systems: An Evolution of Electrochemically Active Materials". ECS Meeting Abstracts MA2022-02, n. 2 (9 ottobre 2022): 138. http://dx.doi.org/10.1149/ma2022-022138mtgabs.

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Energy storage is vital for driving an energy independent world economy that is currently largely dependent on exploiting natural reserves supplemented by oil and gas exports. The field of Li-ion batteries continues to witness burgeoning progress since the commercialization of the first Li-ion battery (LIB) by Sony in 1991, and is at present, clearly the flagship rechargeable battery system. Correspondingly, enormous progress is seen in cathodes, electrolytes as well as anodes [1]. New materials have continuously evolved. Lithiated transition metal oxides despite advances in various systems, are still the flagship cathodes of choice relying on ubiquitous intercalation chemistries. Newer chemistries exploiting alloying and Zintl phase formation focusing on silicon and tin as alternative anodes have also evolved in the last two decades. Similarly, there is tremendous research in the area of alternative energy storage systems beyond lithium-ion intercalation chemistry. Lithium-sulfur batteries (LSB) and Li metal anodes have putatively emerged at the forefront and are the spotlight of increased research activity in recent years. All these systems are unfortunately, plagued by intransigent inferior electronic conductivity, Li-ion conductivity, voltage-specific phase transition related kinetic limitations accompanied with ensuing chemical, physical, and electrochemical challenges. Nano-engineered approaches aided by concomitant progress in science and technology of synthetic and analytical chemistry of advanced materials appear primed for overcoming these hurdles. We initiated work introducing solution-based chemical synthesis strategies for generating nanostructured lithiated transition metal oxides, including anti-site defect-free LiNiO2[2,3]. This work then transitioned into alternative anodes[4] and presently into the Li-S systems holding much promise, albeit major challenges remain to be overcome. We have thus far, implemented dynamic theoretical and experimental strategies to develop engineered electronic and Li-ion conducting nanomaterials showing considerable promise as supporting components augmenting the performance and overcoming many of the limitations affecting these systems. Additionally, we have developed several approaches utilizing nanoscale droplets, nanoparticles, hollow silicon nanotubes (h-SiNTs), cost-effective template derived nanoscale morphologies, scribable and flexible hetero-structured Si architectures, displaying impressive capacities of ~3000 mAh/g with sustained cyclability and high-rate capability in Si anodes [4]. Electrochemical approaches were also developed creating binder-less Si-based thin film anodes with considerable promise. Similarly, engineering approaches were implemented for generating sulfur cathodes in LSBs exploiting the tailored attributes of inorganic, nanocomposite, tethered, and polymeric lithium ion conductors (LIC) coupled with chemically linked complex framework materials (CFM) based matrices for encapsulating S along with novel fine yarn-like and tethered S architectures yielding 5.5 mAh/cm2 – 12 mAh/cm2 areal capacity and ~1200 mAh/g specific capacity with S loadings as high as 20 mg/cm2 displaying ~250 cycles cycling stability [5, 6]. Single layer pouch cells exhibiting 180-200 Wh/kg were also demonstrated. Developing scalable economic approaches, however, remain a key challenge. Engineering strategies were also developed for identifying new Li metal alloy anodes preventing and eliminating dendrite formation. These systems serve as alternative safe anodes to Li metal. This presentation will thus provide an overview of the above systems. Similarly, insights into the promising future in generating tailored functional engineered systems in the rapidly evolving digitally savvy era of the 21st century will also be presented. Finally, the prospects of these systems offering a pathway to potentially achieving energy independence in the near future will also be outlined. References Wang, P.N. Kumta, et al. ACS Nano (2011). C-C. Chang, P.N. Kumta et al. J. Electrochemical Society 147 (2000). C. Chang, P.N. Kumta et al. J. Power Sources 75 (1998). Gattu, P.N. Kumta et al. Nano Research (2017). M. Shanthi, P.N. Kumta et al. Electrochimica Acta (2017). M. Shanthi, P.N. Kumta et al. Applied Energy Materials (2018).

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Jahava, Marlina, Mohd Hafiz Jali, Danusha Pillai, Haziezol Helmi Mohd Yusof, Md Ashadi Md Johari, Aminah Ahmad, Siti Halma Johari, Sulaiman Wadi Harun e Siddharth Thokchom. "Seventh Sense Research Group Home Journals For Authors For Editors For Reviewers Call for Paper May 2023 IJEEE Aim & Scope Editorial Board Paper Submission Current Issue Archives Publication Ethics Guidelines for Authors Guidelines for Editors Guidelines for Reviewer Indexing Article Processing charges Mode of Payment for APC Paper Template Copyright Form Alcohol Sensing Device using Glass Substrates Coated with Agarose Gel and HEC/PVDF Nanomaterial International Journal of Electrical and Electronics Engineering © 2023 by SSRG - IJEEE Journal Volume 10 Issue 4 Year of Publication : 2023 Authors : Marlina Jahava, Mohd Hafiz Jali, Danusha Pillai, Haziezol Helmi Mohd Yusof, Md. Ashadi Md Johari, Aminah Ahmad, Siti Halma Johari, Sulaiman Wadi Harun, Siddharth Thokchom 10.14445/23488379/IJEEE-V10I4P104 pdf How to Cite? Marlina Jahava, Mohd Hafiz Jali, Danusha Pillai, Haziezol Helmi Mohd Yusof, Md. Ashadi Md Johari, Aminah Ahmad, Siti Halma Johari, Sulaiman Wadi Harun, Siddharth Thokchom, "Alcohol Sensing Device using Glass Substrates Coated with Agarose Gel and HEC/PVDF Nanomaterial," SSRG International Journal of Electrical and Electronics Engineering, vol. 10, no. 4, pp. 37-45, 2023. Crossref, https://doi.org/10.14445/23488379/IJEEE-V10I4P104 Abstract: This paper reported the development of an alcohol sensor based on a glass substrate platform. The glass substrate was coated with two nanomaterial types: Hydroxyethylcellulose/Polyvinylidene fluoride (HEC/PVDF) and Agarose Gel, for comparison purposes. Three layers of coating material have been applied to the glass substrate to obtain the optimum sensing response. The coated glass substrate is kept dry for 24 hours before expose to variations of ethanol concentration to investigate the sensing response. A significant response to alcohol concentrations has been observed for both samples due to the changeable refractive index layer of the coating material. The sensitivity improved by a factor of 1.18 and 1.51, respectively, compared to the bared glass. The proposed sensor employed low-cost and commercially available components such as a glass substrate, LED light source and Arduino microcontroller to perform as an alcohol sensor. It prevents using expensive laser-based sensors, which is less practical in real industrial applications. Based on the experiment results, the HEC/PVDF-coated glass produced has demonstrated better results in terms of repeatability, hysteresis, stability and sensitivity as compared to agarose gel-coated glass. Hence the proposed sensor has a decent potential as an alcohol sensor Keywords: Alcohol sensor, Glass substrate, HEC/PVDF, Agarose gel. References: [1] G. 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[CrossRef] [Google Scholar] [Publisher Link] [37] Feng-Bo Yang et al., "A Low-Cost Light-Emitting Diode Induced Fluorescence Detector for Capillary Electrophoresis Based on an Orthogonal Optical Arrangement," Talanta, vol. 78, no. 3, pp. 1155-1158, 2009. [CrossRef] [Google Scholar] [Publisher Link] Quick Links Home Journals Call For Paper Authors Paper submission Preparation Guidelines Review Process Editors Reviewer Guidelines Join as Editor Special Issue Proposal Events Conferences Awards Special Issues SSRG Contact Us Indexing Follow Us Facebook Linkedin Twitter © SSRG International Journals - All right reserved Creative Commons License SSRG site and its metadata are licensed under CC BY-NC-ND Designed by VTS". International Journal of Electrical and Electronics Engineering 10, n. 4 (30 aprile 2023): 37–45. http://dx.doi.org/10.14445/23488379/ijeee-v10i4p104.

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Alotaibi, Nusaybah, Hassan H. Hammud, Nasreen Al Otaibi, Syed Ghazanfar Hussain e Thirumurugan Prakasam. "Novel cobalt–carbon@silica adsorbent". Scientific Reports 10, n. 1 (29 ottobre 2020). http://dx.doi.org/10.1038/s41598-020-75367-0.

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Abstract Recently, carbon nanostructures are of high importance due to their unique characteristics and interesting applications. Pyrolysis of anthracene with cobalt complex Co(2,2′-bipy)Cl2(1), where (2,2′-bipy) is 2,2′-bipyridine, in the absence and presence of silica gave in high yield cobalt-carbon nanocomposite CoCNC (2) and CoCNC@SiO2(3) at 600 °C and 850 °C, respectively. They were characterized using SEM, TEM, PXRD, Raman and XPS. (3) and (2) contain core–shell cobalt(0)/cobalt oxide-graphite with or without silica support. PXRD indicates that (2) contains crystalline hexagonal α-Co and cubic β-Co phases while (3) contains only cubic β-Co phase and silica. The structure of (2) is 3D hierarchical carbon architecture wrapping spherical and elliptical cobalt nanoparticles. (3) consists of graphitized structures around cobalt nanoparticles embedded in the silica matrix. XPS reveals that the nanocomposites contain oxygen functional groups that enhance uptake of cationic dyes. CoCNC@SiO2(3) has higher capacity and thus is better adsorbent of Basic Violet 3 than CoCNC (2). The Langmuir adsorption capacity of (3) is 19.4 mg g−1 while column capacity is 12.55 mg g−1 at 25 °C. Freundlich isotherm and pseudo-second-order kinetic models fit well the adsorption data. Thermodynamics indicate that adsorption(3) is exothermic. Column regeneration was tested for three cycles and Yan et al. was found the best kinetic model.

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Cc, Ko, Wu Y-L, Douglas Wh, Narayanan R e Hu W-S. "In Vitro and In Vivo Tests Of Hydroxyapatite-Gleatin Nanocomposites For Bone Regeneration: A Preliminary Report." MRS Proceedings 823 (2004). http://dx.doi.org/10.1557/proc-823-w13.8.

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AbstractA biomimetic process has been developed to fabricate hydroxyapatite-gelatin (HAP-GEL) nanocomposites for bone regeneration (Chang and Ko et al. 2003). We hypothesize that this newly developed HAP-GEL is osteoconductive and is suitable for tissue engineered scaffolds. This preliminary study is aimed to characterize cell affinity and osseous regeneration of the HAP-GEL. The HAP-GEL was synthesized according to the procedures described in the previous publication. The attachment and proliferation of human fetal osteoblasts on HAP-GEL discs were evaluated using three different gelatin contents (2g, 3g, and 4g). The cells were seeded onto each disc and incubated at 34 degrees Celsius in 5% CO2 air atmosphere. At different time points of cultivation, cells were stained with fluorescein diacetate (FDA) and ethidium bromide (EB) to determine their viability and morphology. To assess the cell proliferation, cells were detached at Days 1, 4, and 7 by trypsinzation and counted. For in vivo tests, HAP-GEL rods were implanted into the proximal femur of Sprague-Dawley rats. One month after the implantation, the femurs were harvested and the undecalcified HAP-GEL-bone sections were stained for histopathology. Four hours after attachment, most cells appeared round in all discs; cell spreading was observed after 24 hours. The highest gelatin content supported a significantly higher cell growth than the others at 7 days. Thus all compositions support satisfactory attachment, spreading and growth. In vivo results showed excellent interfacial bone regeneration. No necrotic tissues were found. In conclusion, the HAP-GEL not only mimics the biochemistry and nanostructures of bone but also supports the attachment, proliferation and differentiation (bone formation) of osteoblasts. The HAP-GEL we developed provides a suitable surface for regeneration.

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Wilde, Gerhard. "Deformation-induced Nanocomposites". MRS Proceedings 977 (2006). http://dx.doi.org/10.1557/proc-977-0977-ff05-03.

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AbstractComposite approaches, e.g. with mutually immiscible constituents or including at least one refractory phase, present a viable and maybe even necessary route for stabilizing massive nanostructured materials against detrimental coarsening under thermal and/or mechanical loading conditions [1]. A different way for nanoscaled composite formation is presented by the nanocrystallization of marginally glass-forming amorphous alloys, such as Al-rich alloys with rare earth and transition metal additions. Such composite systems that are stabilized at nanometer-scaled structure sizes due to diffusion limitations have conventionally been processed by supplying thermal energy for initiating the nanocrystal formation [2]. New opportunities for fabricating massive nanocrystalline composites in bulk quantities and with improved microstructures from such alloys might be based on the plastic deformation of the amorphous quenching products, as indicated by the observation of nanocrystallization in shear bands [3-5].ere, different deformation methods with largely different strain and pressure levels have been applied on rapidly quenched Al-rich metallic glasses in order to investigate the strain-induced nanocrystal formation. The results indicate e.g. that shear straining under a high pressure and to large strain values can produce uniform nanocrystalline structures in bulk samples, which is essential to their functional performance. Moreover, detailed structure analyses indicate that the amorphous structure of the entire sample volume, and not only the shear band regions, might be affected by the plastic deformation. In addition to the significance concerning the understanding of the deformation of glasses, the results also indicate the applicability of the new processing routes for synthesizing massive, porosity-free nanocrystalline materials.[1] G. Wilde, H. Rösner, J. Mater. Sci., in press. [2]G. Wilde, et al., Adv. Engr. Mater. 5 (2003) 125. [3]G. Wilde et al., Mater. Sci. Forum 503-504 (2006) 425. [4] N. Boucharat, et al., Scripta Mater. 53 (2005) 823. [5] R. Hebert, et al., Scripta Mater. 54 (2006) 25.

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Alvarado-Tenorio, Bonifacio, Angel Romo-Uribe e Patrick T. Mather. "Stress-induced Bimodal Ordering in POSS/PCL Biodegradable Shape Memory Nanocomposites". MRS Proceedings 1450 (2012). http://dx.doi.org/10.1557/opl.2012.1327.

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ABSTRACTSimultaneous wide- and small- angle X-ray scattering (WAXS-SAXS) has revealed a stress-induced bimodal orientation of POSS crystals and PCL chains, both in a constrained POSS/PCL crosslinked network architecture with shape memory properties. POSS/PCL nanocomposites with molecular weight of 2,600 g/mol exhibiting shape memory behavior were synthesized and variation of crosslinker molar ratio was used to obtain POSS/PCL networks with different crosslink density (Alvarado-Tenorio et al., Macromolecules, 44, 5682, 2011). In that study it was shown that there are POSS crystals embedded in an amorphous PCL matrix, and the POSS crystals were ordered in a cubic nanostructure. In this work, it will be shown that elongation at room temperature of all the networks yielded a double-induced orientation (90º and 180º) of the POSS crystals, as indicated by the 101 reflection. Moreover, it was also detected stretched-induced crystallization of the otherwise amorphous PCL chains. Furthermore, SAXS data showed long periods in the meridional and equatorial orientations of 630 Å, 90 Å and 45 Å corresponding to a lamellar nanostructure of PCL chains. The induced bimodal orientation of the POSS-PCL molecular network will be correlated with its shape memory properties.

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