The Experts below are selected from a list of 564834 Experts worldwide ranked by ideXlab platform
Chenho Tung - One of the best experts on this subject based on the ideXlab platform.
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quantum dot assembly for light driven multielectron redox reactions such as Hydrogen evolution and co2 reduction
Angewandte Chemie, 2019Co-Authors: Chenho TungAbstract:Light-driven multielectron redox reactions (e.g., Hydrogen (H2 ) evolution, CO2 reduction) have recently appeared at the front of solar-to-fuel conversion. In this Minireview, we focus on the recent advances in establishing semiconductor quantum dot (QD) assemblies to enhance the efficiencies of these light-driven multielectron reduction reactions. Four models of QD assembly are established to promote the sluggish kinetics of multielectron transfer from QDs to cocatalysts, thus leading to an enhanced activity of solar H2 evolution or CO2 reduction. We also forecast the potential applications of QD assemblies in other multielectron redox reactions, such as nitrogen (N2 ) fixation and oxygen (O2 ) evolution from H2 O.
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a cascade cross coupling Hydrogen evolution reaction by visible light catalysis
Journal of the American Chemical Society, 2013Co-Authors: Qingyuan Meng, Chenho Tung, Bin Chen, Ke Feng, Jianji Zhong, Huihui Zhang, Zhijun Li, Lizhu WuAbstract:Cross-deHydrogenative-coupling reaction has long been recognized as a powerful tool to form a C–C bond directly from two different C–H bonds. Most current processes are performed by making use of stoichiometric amounts of oxidizing agents. We describe here a new type of reaction, namely cross-coupling Hydrogen evolution (CCHE), with no use of any sacrificial oxidants, and only Hydrogen (H2) is generated as a side product. By combining eosin Y and a graphene-supported RuO2 nanocomposite (G-RuO2) as a photosensitizer and a catalyst, the desired cross-coupling products and H2 are achieved in quantitative yields under visible light irradiation at room temperature.
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interface directed assembly of a simple precursor of fefe H2ase mimics on cdse qds for photosynthetic Hydrogen evolution in water
Energy and Environmental Science, 2013Co-Authors: Gexia Wang, Feng Wang, Qingyuan Meng, Bin Chen, Ke Feng, Chenho TungAbstract:To prepare a water-soluble catalyst for photocatalytic Hydrogen (H2) evolution, a simple hydrophobic precursor of [FeFe]–H2ase mimics, Fe2S2(CO)6, has been successfully assembled on the surface of CdSe QDs using an interface-directed approach in aqueous/organic solution. The resulting photocatalyst shows the highest efficiency known to date for H2 evolution with a turnover number (TON) of 8781 vs. Fe2S2(CO)6 and an initial turnover frequency (TOF) of 596 h−1 under visible light irradiation in water.
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artificial photosynthetic systems based on fefe Hydrogenase mimics the road to high efficiency for light driven Hydrogen evolution
ACS Catalysis, 2012Co-Authors: Feng Wang, Wenguang Wang, Hongyan Wang, Chenho TungAbstract:Hydrogen (H2) has the potential to replace fossil fuels as the clean energy carrier of the future, particularly if it is produced by water splitting using visible light. Natural [FeFe]-Hydrogenase ([FeFe]-H2ase) is known to catalyze the reversible reduction of protons to H2 with remarkable activity under mild conditions. In this respect, artificial photosynthetic systems for H2 production by using sunlight and [FeFe]-H2ase mimics have attracted much attention, and great progress has been made in recent years. This perspective paper describes our efforts to achieve H2 evolution by [FeFe]-H2ase mimics powered by a photosensitizer (PS). Covalent-linked molecular dyads and a triad, a self-assembled micelle system and a robust, inexpensive, nanocrystal CdTe system will be highlighted.
Wojtek Wlodarski - One of the best experts on this subject based on the ideXlab platform.
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Graphene-like nano-sheets for surface acoustic wave gas sensor applications
Chemical Physics Letters, 2009Co-Authors: R. Arsat, P. G. Spizziri, Scott Gilje, Mojtaba Shafiei, Richard Barry Kaner, Michael Breedon, Kourosh Kalantar-zadeh, Wojtek WlodarskiAbstract:The gas sensing properties of graphene-like nano-sheets deposited on 36° YX lithium tantalate (LiTaO3) surface acoustic wave (SAW) transducers are reported. The thin graphene-like nano-sheets were produced via the reduction of graphite oxide which was deposited on SAW interdigitated transducers (IDTs). Their sensing performance was assessed towards Hydrogen (H2) and carbon monoxide (CO) in a synthetic air carrier gas at room temperature (25 °C) and 40 °C. Raman and X-ray photoelectron spectroscopy (XPS) revealed that the deposited graphite oxide (GO) was not completely reduced creating small, graphitic nanocrystals ∼2.7 nm in size. © 2008 Elsevier B.V.
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polyaniline nanofiber based surface acoustic wave gas sensors effect of nanofiber diameter on hbox h _ 2 response
IEEE Sensors Journal, 2007Co-Authors: A Z Sadek, Wojtek Wlodarski, Christina O Baker, David A Powell, Richard B Kaner, Kourosh KalantarzadehAbstract:A template-free rapidly mixed reaction was employed to synthesize polyaniline nanofibers using chemical oxidative polymerization of aniline. Hydrochloric acid (HCl) and camphor sulfonic acid (CSA) were used in the synthesis to obtain 30- and 50-nm average diameter polyaniline nanofibers. The nanofibers were deposited onto layered ZnO/64deg YX LiNbO3 surface-acoustic-wave transducers. The sensors were tested toward Hydrogen (H2) gas while operating at room temperature. The dopant for the polyaniline nanofiber synthesis was found to have a significant effect on the device sensitivity. The sensor response was found to be larger for the 50-nm diameter CSA-doped nanofiber based sensors, while the response and recovery times were faster for the 30-nm diameter HCl-doped nanofibers
Arokia Nathan - One of the best experts on this subject based on the ideXlab platform.
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high mobility nanocrystalline silicon thin film transistors fabricated by plasma enhanced chemical vapor deposition
Applied Physics Letters, 2005Co-Authors: Andrei Sazonov, Arokia NathanAbstract:Hydrogenated nanocrystalline silicon (nc-Si:H) films were deposited by using 13.56MHz plasma-enhanced chemical vapor deposition at 260°C by means of a silane (SiH4) plasma heavily diluted with Hydrogen (H2). The high-quality nc-Si:H film showed an oxygen concentration (CO) of ∼1.5×1017at.∕cm3 and a dark conductivity (σd) of ∼10−6S∕cm, while the Raman crystalline volume fraction (Xc) was over 80%. Top-gate nc-Si:H thin-film transistors employing an optimized ∼100nm nc-Si:H channel layer exhibited a field-effect mobility (μFE) of ∼150cm2∕Vs, a threshold voltage (VT) of ∼2V, a subthreshold slope (S) of ∼0.25V∕dec, and an ON∕OFF current ratio of ∼106.
Qingyuan Meng - One of the best experts on this subject based on the ideXlab platform.
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a cascade cross coupling Hydrogen evolution reaction by visible light catalysis
Journal of the American Chemical Society, 2013Co-Authors: Qingyuan Meng, Chenho Tung, Bin Chen, Ke Feng, Jianji Zhong, Huihui Zhang, Zhijun Li, Lizhu WuAbstract:Cross-deHydrogenative-coupling reaction has long been recognized as a powerful tool to form a C–C bond directly from two different C–H bonds. Most current processes are performed by making use of stoichiometric amounts of oxidizing agents. We describe here a new type of reaction, namely cross-coupling Hydrogen evolution (CCHE), with no use of any sacrificial oxidants, and only Hydrogen (H2) is generated as a side product. By combining eosin Y and a graphene-supported RuO2 nanocomposite (G-RuO2) as a photosensitizer and a catalyst, the desired cross-coupling products and H2 are achieved in quantitative yields under visible light irradiation at room temperature.
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interface directed assembly of a simple precursor of fefe H2ase mimics on cdse qds for photosynthetic Hydrogen evolution in water
Energy and Environmental Science, 2013Co-Authors: Gexia Wang, Feng Wang, Qingyuan Meng, Bin Chen, Ke Feng, Chenho TungAbstract:To prepare a water-soluble catalyst for photocatalytic Hydrogen (H2) evolution, a simple hydrophobic precursor of [FeFe]–H2ase mimics, Fe2S2(CO)6, has been successfully assembled on the surface of CdSe QDs using an interface-directed approach in aqueous/organic solution. The resulting photocatalyst shows the highest efficiency known to date for H2 evolution with a turnover number (TON) of 8781 vs. Fe2S2(CO)6 and an initial turnover frequency (TOF) of 596 h−1 under visible light irradiation in water.
Makoto Konagai - One of the best experts on this subject based on the ideXlab platform.
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high quality aluminum oxide passivation layer for crystalline silicon solar cells deposited by parallel plate plasma enhanced chemical vapor deposition
Applied Physics Express, 2010Co-Authors: Shinsuke Miyajima, Junpei Irikawa, Akira Yamada, Makoto KonagaiAbstract:We investigated Hydrogenated aluminum oxide (a-Al1-xOx:H) as a high quality rear surface passivation layer of crystalline silicon solar cells. The a-Al1-xOx:H films were deposited by plasma-enhanced chemical vapor deposition (PECVD) using a mixture of trimethylaluminum (TMA), carbon dioxide (CO2), and Hydrogen (H2) at a low substrate temperature of about 200 °C. The ratio of CO2 to TMA during deposition and thermal annealing after the film deposition are the key factors in achieving high quality passivation. A 28-nm-thick a-Al1-xOx:H film deposited by PECVD showed a low surface recombination velocity of about 10 cm/s.
