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1.
An Integrated Photoelectrochemical–Chemical Loop for Solar‐Driven Overall Splitting of Hydrogen Sulfide 下载免费PDF全文
Xu Zong Jingfeng Han Brian Seger Hongjun Chen Gaoqing Lu Can Li Lianzhou Wang 《Angewandte Chemie (International ed. in English)》2014,53(17):4399-4403
Abundant and toxic hydrogen sulfide (H2S) from industry and nature has been traditionally considered a liability. However, it represents a potential resource if valuable H2 and elemental sulfur can be simultaneously extracted through a H2S splitting reaction. Herein a photochemical‐chemical loop linked by redox couples such as Fe2+/Fe3+ and I?/I3? for photoelectrochemical H2 production and H2S chemical absorption redox reactions are reported. Using functionalized Si as photoelectrodes, H2S was successfully split into elemental sulfur and H2 with high stability and selectivity under simulated solar light. This new conceptual design will not only provide a possible route for using solar energy to convert H2S into valuable resources, but also sheds light on some challenging photochemical reactions such as CH4 activation and CO2 reduction. 相似文献
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Matthew V. Sheridan Ying Wang Degao Wang Ludovic Troian‐Gautier Prof. Christopher J. Dares Benjamin D. Sherman Prof. Thomas J. Meyer 《Angewandte Chemie (International ed. in English)》2018,57(13):3449-3453
Light‐driven water splitting was achieved using a dye‐sensitized mesoporous oxide film and the oxidation of bromide (Br?) to bromine (Br2) or tribromide (Br3?). The chemical oxidant (Br2 or Br3?) is formed during illumination at the photoanode and used as a sacrificial oxidant to drive a water oxidation catalyst (WOC), here demonstrated using [Ru(bda)(pic)2], ( 1 ; pic=picoline, bda=2,2′‐bipyridine‐6,6′‐dicarboxylate). The photochemical oxidation of bromide produces a chemical oxidant with a potential of 1.09 V vs. NHE for the Br2/Br? couple or 1.05 V vs. NHE for the Br3?/Br? couple, which is sufficient to drive water oxidation at 1 (RuV/IV≈1.0 V vs. NHE at pH 5.6). At pH 5.6, using a 0.2 m acetate buffer containing 40 mm LiBr and the [Ru(4,4′‐PO3H2‐bpy)(bpy)2]2+ ( RuP 2+, bpy=2,2′‐bipyridine) chromophore dye on a SnO2/TiO2 core–shell electrode resulted in a photocurrent density of around 1.2 mA cm?2 under approximately 1 Sun illumination and a Faradaic efficiency upon addition of 1 of 77 % for oxygen evolution. 相似文献
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Dr. Ling Zhang Zhongkang Han Prof. Wenzhong Wang Xiaoman Li Yang Su Dong Jiang Dr. Xiaoling Lei Dr. Songmei Sun 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(50):18089-18094
A suitable photocatalyst for overall water splitting has been produced by overcoming the disadvantage of the band structure in bulk BiOCl by reducing the thickness to the quantum scale. The ultrathin BiOCl nanosheets with surface/subsurface defects realized the solar‐driven pure water splitting in the absence of any co‐catalysts or sacrificial agent. These surface defects cannot only shift both the valence band and conduction band upwards for band‐gap narrowing but also promote charge‐carrier separation. The amount of defects in the outer layer surface of BiOCl results in an enhancement of carrier density and faster charge transport. First‐principles calculations provide clear evidence that the formation of surface oxygen vacancies is easier for the ultrathin BiOCl nanosheets than for its thicker counterpart. These defects can serve as active sites to effectively adsorb and dissociate H2O molecules, resulting in a significantly improved water‐splitting performance. 相似文献
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Dr. Khurram Saleem Joya Dr. Yasir F. Joya Prof. Kasim Ocakoglu Prof. Roel van de Krol 《Angewandte Chemie (International ed. in English)》2013,52(40):10426-10437
The development of new energy materials that can be utilized to make renewable and clean fuels from abundant and easily accessible resources is among the most challenging and demanding tasks in science today. Solar‐powered catalytic water‐splitting processes can be exploited as a source of electrons and protons to make clean renewable fuels, such as hydrogen, and in the sequestration of CO2 and its conversion into low‐carbon energy carriers. Recently, there have been tremendous efforts to build up a stand‐alone solar‐to‐fuel conversion device, the “artificial leaf”, using light and water as raw materials. An overview of the recent progress in electrochemical and photo‐electrocatalytic water splitting devices is presented, using both molecular water oxidation complexes (WOCs) and nano‐structured assemblies to develop an artificial photosynthetic system. 相似文献
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Photoelectrochemical and Photovoltaic Characteristics of Amorphous‐Silicon‐Based Tandem Cells as Photocathodes for Water Splitting 下载免费PDF全文
Jürgen Ziegler Dr. Bernhard Kaiser Prof. Dr. Wolfram Jaegermann Félix Urbain Jan‐Philipp Becker Dr. Vladimir Smirnov Dr. Friedhelm Finger 《Chemphyschem》2014,15(18):4026-4031
In this study amorphous silicon tandem solar cells are successfully utilized as photoelectrodes in a photoelectrochemical cell for water electrolysis. The tandem cells are modified with various amounts of platinum and are combined with a ruthenium oxide counter electrode. In a two‐electrode arrangement this system is capable of splitting water without external bias with a short‐circuit current of 4.50 mA cm?2. On the assumption that no faradaic losses occur, a solar‐to‐hydrogen efficiency of 5.54 % is achieved. In order to identify the relevant loss processes, additional three‐electrode measurements were performed for each involved half‐cell. 相似文献
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Jing Tang Jun Li Peimei Da Yongcheng Wang Prof. Gengfeng Zheng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(32):11288-11299
Photoelectrochemical sensing represents a unique means for chemical and biological detection, with foci of optimizing semiconductor composition and electronic structures, surface functionalization layers, and chemical detection methods. Here, we have briefly discussed our recent developments of TiO2 nanowire‐based photoelectrochemical sensing, with particular emphasis on three main detection mechanisms and corresponding examples. We have also demonstrated the use of the photoelectrochemical sensing of real‐time molecular reaction kinetic measurements, as well as direct interfacing of living cells and probing of cellular functions. 相似文献
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Efficient Hole Extraction from a Hole‐Storage‐Layer‐Stabilized Tantalum Nitride Photoanode for Solar Water Splitting 下载免费PDF全文
Guiji Liu Ping Fu Lingyu Zhou Pengli Yan Chunmei Ding Dr. Jingying Shi Prof. Can Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(27):9624-9628
One of the major hurdles that impedes the practical application of photoelectrochemical (PEC) water splitting is the lack of stable photoanodes with low onset potentials. Here, we report that the Ni(OH)x/MoO3 bilayer, acting as a hole‐storage layer (HSL), efficiently harvests and stores holes from Ta3N5, resulting in at least 24 h of sustained water oxidation at the otherwise unstable Ta3N5 electrode and inducing a large cathodic shift of ≈600 mV in the onset potential of the Ta3N5 electrode. 相似文献
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Fluorine‐Doped Porous Single‐Crystal Rutile TiO2 Nanorods for Enhancing Photoelectrochemical Water Splitting 下载免费PDF全文
Wen Qi Fang Dr. Ziyang Huo Dr. Porun Liu Xue Lu Wang Dr. Miao Zhang Dr. Yi Jia Dr. Haimin Zhang Prof. Huijun Zhao Prof. Hua Gui Yang Prof. Xiangdong Yao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(36):11439-11444
Fluorine‐doped hierarchical porous single‐crystal rutile TiO2 nanorods have been synthesized through a silica template method, in which F? ions acts as both n‐type dopants and capping agents to make the isotropic growth of the nanorods. The combination of high crystallinity, abundant surface reactive sites, large porosity, and improved electronic conductivity leads to an excellent photoelectrochemical activity. The photoanode made of F‐doped porous single crystals displays a remarkably enhanced solar‐to‐hydrogen conversion efficiency (≈0.35 % at ?0.33 V vs. Ag/AgCl) under 100 mW cm?2 of AM=1.5 solar simulator illumination that is ten times of the pristine solid TiO2 single crystals. 相似文献
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Efficient Visible‐Light‐Driven Z‐Scheme Overall Water Splitting Using a MgTa2O6−xNy /TaON Heterostructure Photocatalyst for H2 Evolution 下载免费PDF全文
Shanshan Chen Yu Qi Dr. Takashi Hisatomi Qian Ding Tomohiro Asai Zheng Li Dr. Su Su Khine Ma Prof. Fuxiang Zhang Prof. Kazunari Domen Prof. Can Li 《Angewandte Chemie (International ed. in English)》2015,54(29):8498-8501
An (oxy)nitride‐based heterostructure for powdered Z‐scheme overall water splitting is presented. Compared with the single MgTa2O6?xNy or TaON photocatalyst, a MgTa2O6?xNy /TaON heterostructure fabricated by a simple one‐pot nitridation route was demonstrated to effectively suppress the recombination of carriers by efficient spatial charge separation and decreased defect density. By employing Pt‐loaded MgTa2O6?xNy /TaON as a H2‐evolving photocatalyst, a Z‐scheme overall water splitting system with an apparent quantum efficiency (AQE) of 6.8 % at 420 nm was constructed (PtOx‐WO3 and IO3?/I? pairs were used as an O2‐evolving photocatalyst and a redox mediator, respectively), the activity of which is circa 7 or 360 times of that using Pt‐TaON or Pt‐MgTa2O6?xNy as a H2‐evolving photocatalyst, respectively. To the best of our knowledge, this is the highest AQE among the powdered Z‐scheme overall water splitting systems ever reported. 相似文献
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Xiuxiu Han Steffen Heuser Dr. Xili Tong Dr. Nianjun Yang Prof. Dr. Xiang-Yun Guo Prof. Dr. Xin Jiang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(16):3586-3590
Cubic silicon carbide (3C-SiC) material feature a suitable bandgap and high resistance to photocorrosion. Thus, it has been emerged as a promising semiconductor for hydrogen evolution. Here, the relationship between the photoelectrochemical properties and the microstructures of different SiC materials is demonstrated. For visible-light-derived water splitting to hydrogen production, nanocrystalline, microcrystalline and epitaxial (001) 3C-SiC films are applied as the photocathodes. The epitaxial 3C-SiC film presents the highest photoelectrochemical activity for hydrogen evolution, because of its perfect (001) orientation, high phase purity, low resistance, and negative conduction band energy level. This finding offers a strategy to design SiC-based photocathodes with superior photoelectrochemical performances. 相似文献
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Wataru Kurashige Yutaro Mori Shuhei Ozaki Masanobu Kawachi Sakiat Hossain Tokuhisa Kawawaki Cameron J. Shearer Akihide Iwase Gregory F. Metha Seiji Yamazoe Akihiko Kudo Yuichi Negishi 《Angewandte Chemie (International ed. in English)》2020,59(18):7076-7082
The activity of many water‐splitting photocatalysts could be improved by the use of RhIII–CrIII mixed oxide (Rh2?xCrxO3) particles as cocatalysts. Although further improvement of water‐splitting activity could be achieved if the size of the Rh2?xCrxO3 particles was decreased further, it is difficult to load ultrafine (<2 nm) Rh2?xCrxO3 particles onto a photocatalyst by using conventional loading methods. In this study, a new loading method was successfully established and was used to load Rh2?xCrxO3 particles with a size of approximately 1.3 nm and a narrow size distribution onto a BaLa4Ti4O15 photocatalyst. The obtained photocatalyst exhibited an apparent quantum yield of 16 %, which is the highest achieved for BaLa4Ti4O15 to date. Thus, the developed loading technique of Rh2?xCrxO3 particles is extremely effective at improving the activity of the water‐splitting photocatalyst BaLa4Ti4O15. This method is expected to be extended to other advanced water‐splitting photocatalysts to achieve higher quantum yields. 相似文献
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T. Gamze Ulusoy Ghobadi Amir Ghobadi Muhammed Buyuktemiz Elif Akhuseyin Yildiz Dilara Berna Yildiz H. Gul Yaglioglu Yavuz Dede Ekmel Ozbay Ferdi Karadas 《Angewandte Chemie (International ed. in English)》2020,59(10):4082-4090
Herein, we establish a simple synthetic strategy affording a heterogeneous, precious metal‐free, dye‐sensitized photoelectrode for water oxidation, which incorporates a Prussian blue (PB) structure for the sensitization of TiO2 and water oxidation catalysis. Our approach involves the use of a Fe(CN)5 bridging group not only as a cyanide precursor for the formation of a PB‐type structure but also as an electron shuttle between an organic chromophore and the catalytic center. The resulting hetero‐functional PB‐modified TiO2 electrode demonstrates a low‐cost and easy‐to‐construct photoanode, which exhibits favorable electron transfers with a remarkable excited state lifetime on the order of nanoseconds and an extended light absorption capacity of up to 500 nm. Our approach paves the way for a new family of precious metal‐free robust dye‐sensitized photoelectrodes for water oxidation, in which a variety of common organic chromophores can be employed in conjunction with CoFe PB structures. 相似文献
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Hierarchical NiCo2O4 Hollow Microcuboids as Bifunctional Electrocatalysts for Overall Water‐Splitting 下载免费PDF全文
Xuehui Gao Hongxiu Zhang Quanguo Li Prof. Xuegong Yu Prof. Zhanglian Hong Prof. Xingwang Zhang Dr. Chengdu Liang Prof. Zhan Lin 《Angewandte Chemie (International ed. in English)》2016,55(21):6290-6294
Bifunctional electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline electrolyte may improve the efficiency of overall water splitting. Nickel cobaltite (NiCo2O4) has been considered a promising electrode material for the OER. However, NiCo2O4 that can be used as an electrocatalyst in HER has not been studied yet. Herein, we report self‐assembled hierarchical NiCo2O4 hollow microcuboids for overall water splitting including both the HER and OER reactions. The NiCo2O4 electrode shows excellent activity toward overall water splitting, with 10 mA cm?2 water‐splitting current reached by applying just 1.65 V and 20 mA cm?2 by applying just 1.74 V across the two electrodes. The synthesis of NiCo2O4 microflowers confirms the importance of structural features for high‐performance overall water splitting. 相似文献
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Photoelectrochemical Hydrogen Production in Alkaline Solutions Using Cu2O Coated with Earth‐Abundant Hydrogen Evolution Catalysts 下载免费PDF全文
Carlos G. Morales‐Guio Laurent Liardet Dr. Matthew T. Mayer Dr. S. David Tilley Prof. Dr. Michael Grätzel Prof. Dr. Xile Hu 《Angewandte Chemie (International ed. in English)》2015,54(2):664-667
The splitting of water into hydrogen and oxygen molecules using sunlight is an attractive method for solar energy storage. Until now, photoelectrochemical hydrogen evolution is mostly studied in acidic solutions, in which the hydrogen evolution is more facile than in alkaline solutions. Herein, we report photoelectrochemical hydrogen production in alkaline solutions, which are more favorable than acidic solutions for the complementary oxygen evolution half‐reaction. We show for the first time that amorphous molybdenum sulfide is a highly active hydrogen evolution catalyst in basic medium. The amorphous molybdenum sulfide catalyst and a Ni–Mo catalyst are then deposited on surface‐protected cuprous oxide photocathodes to catalyze sunlight‐driven hydrogen production in 1 M KOH. The photocathodes give photocurrents of ?6.3 mA cm?2 at the reversible hydrogen evolution potential, the highest yet reported for a metal oxide photocathode using an earth‐abundant hydrogen evolution reaction catalyst. 相似文献
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Photochemical,Electrochemical, and Photoelectrochemical Water Oxidation Catalyzed by Water‐Soluble Mononuclear Ruthenium Complexes 下载免费PDF全文
Ting‐Ting Li Wei‐Liang Zhao Prof. Dr. Yong Chen Fu‐Min Li Chuan‐Jun Wang Yong‐Hua Tian Prof. Dr. Wen‐Fu Fu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(43):13957-13964
Two mononuclear ruthenium complexes [Ru(H2tcbp)(isoq)2] ( 1 ) and [Ru(H2tcbp)(pic)2] ( 2 ) (H4tcbp=4,4′,6,6′‐tetracarboxy‐2,2′‐bipyridine, isoq=isoquinoline, pic=4‐picoline) are synthesized and fully characterized. Two spare carboxyl groups on the 4,4′‐positions are introduced to enhance the solubility of 1 and 2 in water and to simultaneously allow them to tether to the electrode surface by an ester linkage. The photochemical, electrochemical, and photoelectrochemical water oxidation performance of 1 in neutral aqueous solution is investigated. Under electrochemical conditions, water oxidation is conducted on the deposited indium‐tin‐oxide anode, and a turnover number higher than 15,000 per water oxidation catalyst (WOC) 1 is obtained during 10 h of electrolysis under 1.42 V vs. NHE, corresponding to a turnover frequency of 0.41 s?1. The low overpotential (0.17 V) of electrochemical water oxidation for 1 in the homogeneous solution enables water oxidation under visible light by using [Ru(bpy)3]2+ ( P1 ) (bpy=2,2′‐bipyridine) or [Ru(bpy)2(4,4′‐(COOEt)2‐bpy)]2+ ( P2 ) as a photosensitizer. In a three‐component system containing 1 or 2 as a light‐driven WOC, P1 or P2 as a photosensitizer, and Na2S2O8 or [CoCl(NH3)5]Cl2 as a sacrificial electron acceptor, a high turnover frequency of 0.81 s?1 and a turnover number of up to 600 for 1 under different catalytic conditions are achieved. In a photoelectrochemical system, the WOC 1 and photosensitizer are immobilized together on the photoanode. The electrons efficiently transfer from the WOC to the photogenerated oxidizing photosensitizer, and a high photocurrent density of 85 μA cm?2 is obtained by applying 0.3 V bias vs. NHE. 相似文献