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Jiaguo Yu - One of the best experts on this subject based on the ideXlab platform.
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graphdiyne a new photocatalytic co2 reduction Cocatalyst
Advanced Functional Materials, 2019Co-Authors: Feiyan Xu, Kai Meng, Jingsan Xu, Jiaguo YuAbstract:Exploring new and efficient Cocatalysts to boost photocatalytic CO2 reduction is of critical importance for solar‐to‐fuel conversion. As an emerging carbon allotrope, graphdiyne (GDY) features 2D characteristics and unique carbon–carbon bonds. Herein, a novel GDY Cocatalyst coupled TiO2 nanofibers for boosted photocatalytic CO2 reduction, synthesized by an electrostatic self‐assembly approach is reported. First‐principle calculation and in situ X‐ray photoelectron spectroscopy measurement reveal that the delocalized electrons in GDY can hybrid with the empty orbitals in TiO2 within the TiO2/GDY network, leading to the formation of an internal electric field at the interfaces, pointing from GDY to TiO2. The theoretical simulation further implies strong chemisorption and deformation of CO2 molecules upon GDY, which can be verified by in situ diffuse reflectance infrared Fourier transform spectroscopy. These effects, in combination with the photothermal effect of GDY, result in enhanced charge separation and directed electron transfer, enhanced CO2 adsorption and activation as well as accelerated catalytic reactions over the TiO2/GDY heterostructure, thereby resulting in significantly improved CO2 photoreduction efficiency and meanwhile with remarkable selectivity. This work demonstrates that GYD can function as a highly effective Cocatalyst for solar energy harvesting and may be used in other catalysis processes.
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Dual Cocatalysts in TiO2 Photocatalysis.
Advanced Materials, 2019Co-Authors: Aiyun Meng, Liuyang Zhang, Bei Cheng, Jiaguo YuAbstract:: Semiconductor photocatalysis is recognized as a promising strategy to simultaneously address energy needs and environmental pollution. Titanium dioxide (TiO2 ) has been investigated for such applications due to its low cost, nontoxicity, and high chemical stability. However, pristine TiO2 still suffers from low utilization of visible light and high photogenerated-charge-carrier recombination rate. Recently, TiO2 photocatalysts modified by dual Cocatalysts with different functions have attracted much attention due to the extended light absorption, enhanced reactant adsorption, and promoted charge-carrier-separation efficiency granted by various Cocatalysts. Recent progress on the component and structural design of dual Cocatalysts in TiO2 photocatalysts is summarized. Depending on their components, dual Cocatalysts decorated on TiO2 photocatalysts can be divided into the following categories: bimetallic Cocatalysts, metal-metal oxide/sulfide Cocatalysts, metal-graphene Cocatalysts, and metal oxide/sulfide-graphene Cocatalysts. Depending on their architecture, they can be categorized into randomly deposited binary Cocatalysts, facet-dependent selective-deposition binary Cocatalysts, and core-shell structural binary Cocatalysts. Concluding perspectives on the challenges and opportunities for the further exploration of dual Cocatalyst-modified TiO2 photocatalysts are presented.
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enhanced photocatalytic h 2 production activity of anatase tio 2 nanosheet by selectively depositing dual Cocatalysts on 101 and 001 facets
Applied Catalysis B-environmental, 2016Co-Authors: Aiyun Meng, Bei Cheng, Jiaguo Yu, Jun Zhang, Difa XuAbstract:Abstract The photocatalytic hydrogen production using solar energy through water splitting has received great attention due to the increasingly serious energy crisis. Herein, we report the controlled preparation of anatase TiO 2 nanosheet photocatalyst by selectively depositing Co 3 O 4 nanoparticles (NPs) as water oxidation Cocatalyst (WOC) and Pt NPs as water reduction Cocatalyst (WRC) on {001} and {101} facets, respectively, using a two-step photodeposition method. The prepared TiO 2 -Co 3 O 4 -Pt composite photocatalyst exhibits a greatly enhanced photocatalytic H 2 -production activity at the optimal weight percentage of Co 3 O 4 and Pt (both 1.0 wt%), exceeding that of TiO 2 nanosheet deposited with single Co 3 O 4 or Pt Cocatalyst by 9.4 and 1.8 times, respectively. The enhanced H 2 -production activity is due to the synergetic effect of surface heterojunction between {001} and {101} facets and selective deposition of Co 3 O 4 and Pt dual-Cocatalysts at {001} and{101} facets, respectively. The former is beneficial for the transfer and separation of charge carriers, the latter can reduce the recombination rate of photogenerated electrons and holes and also catalyze the redox reactions. This work will provide a new route for the rational design and fabrication of highly efficient photocatalysts with dual-Cocatalysts through selective surface deposition.
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amorphous molybdenum sulfide as highly efficient electron Cocatalyst for enhanced photocatalytic h2 evolution
Applied Catalysis B-environmental, 2016Co-Authors: Huogen Yu, Ping Wang, Pian Xiao, Jiaguo YuAbstract:Abstract Exploiting novel and high-performance electron-Cocatalysts without noble metallic element is of great significance for photocatalytic H 2 -evolution reaction. Molybdenum sulfide is one of the promising candidates of such electron-Cocatalysts, but its present performance is intrinsically restrained by the scarce active sites of unsaturated S atoms. In this study, amorphous MoS x (a-MoS x ) nanoparticles were directly anchored on the g-C 3 N 4 surface by an adsorption-in situ transformation method with the aim of improving photocatalytic H 2 -evolution activity. It was found that compared with the crystalline molybdenum sulfide (c-MoS 2 ), the a-MoS x Cocatalyst clearly exhibited more unsaturated active S atoms due to its highly irregular arrangement structure. Photocatalytic experimental results suggested that the H 2 -evolution activity of g-C 3 N 4 photocatalyst could be obviously improved by loading a-MoS x Cocatalyst, which is obviously higher than that of unmodified g-C 3 N 4 and c-MoS 2 /g-C 3 N 4 . More importantly, in addition to the g-C 3 N 4 , the amorphous MoS x could also work as the efficient electron Cocatalyst to greatly enhance the photocatalytic performance of conventional H 2 -evolution materials such as TiO 2 (a typical UV-light photocatalyst) and CdS (a typical Vis-light photocatalyst). On the basis of the present results, an electron-Cocatalyst mechanism of amorphous MoS x was proposed to account for the improved photocatalytic H 2 -evolution activity, namely, the amorphous MoS x can provide more unsaturated active S atoms as the efficient active sites to rapidly capture protons from solution, and then promote the direct reduction of H + to H 2 by photogenerated electrons. Considering its low cost and high efficiency, the amorphous MoS x Cocatalyst would have great potential for the development of high-performance photocatalytic materials used in various fields.
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enhanced photoinduced stability and photocatalytic activity of cds by dual amorphous Cocatalysts synergistic effect of ti iv hole Cocatalyst and ni ii electron Cocatalyst
Journal of Physical Chemistry C, 2016Co-Authors: Huogen Yu, Ping Wang, Xiao Huang, Jiaguo YuAbstract:CdS is one of the most well-known and important visible-light photocatalytic materials for water splitting to produce hydrogen energy. Owing to its serious photocorrosion property (poor photoinduced stability), however, CdS photocatalyst can unavoidably be oxidized to form S0 by its photogenerated holes, causing an obviously decreased photocatalytic performance. In this study, to improve the photoinduced stability of CdS photocatalyst, amorphous TiO2 (referred to as Ti(IV)) as a hole Cocatalyst was successfully loaded on the CdS surface to prepare Ti(IV)/CdS photocatalysts. It was found that the resultant Ti(IV)/CdS photocatalyst exhibited an obviously enhanced photocatalytic stability, namely, its deactivation rate clearly decreased from 37.9% to 13.5% after five cycles of photocatalytic reactions. However, its corresponding photocatalytic activity only showed a very limited increase (ca. 37.4%) compared with the naked CdS. To further improve its photocatalytic performance, the amorphous Ni(II) as an ele...
Kazunari Domen - One of the best experts on this subject based on the ideXlab platform.
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Effect of Hydrogen and Oxygen Evolution Cocatalysts on Photocatalytic Activity of GaN:ZnO
European Journal of Inorganic Chemistry, 2013Co-Authors: Anke Xiong, Kazuhiko Maeda, Takashi Hisatomi, Taizo Yoshinaga, Takahiro Ikeda, Masaki Takashima, Toru Setoyama, Toshiharu Teranishi, Kazunari DomenAbstract:The coloading effect of H2 and O2 evolution Cocatalysts on the overall water splitting reaction was investigated using a solid solution of GaN and ZnO (hereafter termed GaN:ZnO) as a photocatalyst. GaN:ZnO was modified with nanoparticulate Mn3O4, RuO2, and IrO2 as O2 evolution Cocatalysts and with core/shell-type Rh/Cr2O3 composites as H2 evolution Cocatalysts. The photocatalytic activity of the coloaded samples for overall water splitting was higher than that of the samples modified with either of the O2 or H2 evolution Cocatalysts alone. The activity enhancement induced by coloading was comparable for the three O2 evolution Cocatalysts investigated at the optimized loading amounts. Loading of a more efficient Rh/Cr2O3 Cocatalyst prepared by adsorption of Rh nanoparticles further improved the photocatalytic activity. It was concluded that a simultaneous improvement in both oxidation and reduction reactions was effective at enhancing the photocatalytic activity of GaN:ZnO, whereas the reduction reactions limited the overall reaction rate of the coloaded system more significantly.
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photocatalytic water splitting using modified gan zno solid solution under visible light long time operation and regeneration of activity
Journal of the American Chemical Society, 2012Co-Authors: Tomoyuki Ohno, Kazuhiko Maeda, Takashi Hisatomi, Kazunari DomenAbstract:Overall water splitting using GaN:ZnO solid solution photocatalyst modified with Rh2–yCryO3 nanoparticles as H2 evolution Cocatalysts under visible light (400 < λ < 500 nm) was examined with respect to long-term durability and regeneration of photocatalytic activity. The rate of visible light water splitting remained unchanged for 3 months (2160 h), producing H2 and O2 continuously at a stoichiometric amount. After 6 months of operation, a 50% loss of the initial activity occurred. Regeneration treatment of deactivated catalysts was attempted by reloading the Rh2–yCryO3 Cocatalyst. The degree of activity regeneration depended on the reloading amount. Up to 80% of the initial activity for H2 evolution could be recovered under optimal treatment conditions. It was also found that deactivation of GaN:ZnO was suppressed to some extent by prior coloading of an O2 evolution Cocatalyst, which helped to suppress oxidative decomposition of GaN:ZnO by valence band holes, thereby improving the durability.
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photocatalytic water splitting recent progress and future challenges
Journal of Physical Chemistry Letters, 2010Co-Authors: Kazuhiko Maeda, Kazunari DomenAbstract:Water splitting to form hydrogen and oxygen using solar energy in the presence of semiconductor photocatalysts has long been studied as a potential means of clean, large-scale fuel production. In general, overall water splitting can be achieved when a photocatalyst is modified with a suitable Cocatalyst. It is therefore important to develop both photocatalysts and Cocatalysts. In the past five years, there has been significant progress in water splitting photocatalysis, especially in the development of Cocatalysts and related physical and materials chemistry. This work describes the state of the art and future challenges in photocatalytic water splitting, with a focus on the recent progress of our own research.
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photocatalytic hydrogen evolution from water using copper gallium sulfide under visible light irradiation
Journal of Physical Chemistry C, 2010Co-Authors: Masashi Tabata, Kazuhiko Maeda, Takahiro Ishihara, Tsutomu Minegishi, Tsuyoshi Takata, Kazunari DomenAbstract:Copper gallium sulfide with a chalcopyrite-type structure (CuGa3S5) and a band gap of ca. 2.4 eV was prepared by a solid-state reaction. The as-prepared CuGa3S5 exhibited photocatalytic hydrogen evolution activity in an aqueous solution containing Na2S and Na2SO3 as sacrificial electron donors under visible-light irradiation (λ > 420 nm), even without a Cocatalyst, such as platinum (Pt). The photocatalytic activity, however, was improved by the deposition of noble metal Cocatalysts. Among the noble metals tested, rhodium (Rh) was found to be the most effective Cocatalyst to improve the H2 evolution activity, which was 2.5 times that achieved without a Cocatalyst. Dispersion of base sulfides, including nickel sulfide (NiS) and iron sulfide (FeS), into the reactant solution containing CuGa3S5 also increased the activity. The activity under optimized conditions (5.0 wt % NiS/CuGa3S5) was 3 times that of a similarly optimized Rh/CuGa3S5. The results of electrochemical measurements and photocatalytic reactions...
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role and function of noble metal cr layer core shell structure Cocatalysts for photocatalytic overall water splitting studied by model electrodes
Journal of Physical Chemistry C, 2009Co-Authors: Masaaki Yoshida, Kazuhiko Maeda, Kazuhiro Takanabe, Akio Ishikawa, Jun Kubota, Yoshihisa Sakata, Yasunari Ikezawa, Kazunari DomenAbstract:The mechanism of hydrogen evolution by a core/shell noble-metal/Cr2O3 particulate as a highly efficient Cocatalyst for overall water splitting under visible light using the photocatalyst (Ga1−xZnx)(N1−xOx) is investigated by electrochemical and in situ spectroscopic measurements of model electrodes. The electrodes are prepared by electrochemical deposition of 1.8−3.5 nm thick Cr2O3 films on Rh and Pt plates and are evaluated as model systems of Rh/Cr2O3 and Pt/Cr2O3 core/shell particulates, which have previously been applied effectively as Cocatalysts for hydrogen evolution in this system. Proton adsorption/desorption and H2 evolution currents are observed for both the Cr2O3-coated and the bare electrodes, and the infrared absorption band due to Pt−H stretching (2039 cm−1) is apparent for both the coated and the bare electrodes. These observations indicate that the Cr2O3 layer does not interfere with proton reduction or hydrogen evolution and that proton reduction takes place at the Cr2O3/Pt interface. Ho...
Huogen Yu - One of the best experts on this subject based on the ideXlab platform.
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co modification of amorphous ti iv hole Cocatalyst and ni oh 2 electron Cocatalyst for enhanced photocatalytic h2 production performance of tio2
Applied Surface Science, 2017Co-Authors: Ping Wang, Xuefei Wang, Yanggang Lu, Huogen YuAbstract:Abstract Highly efficient TiO 2 photocatalysts co-modified by amorphous-Ti(IV) hole Cocatalyst and Ni(OH) 2 electron Cocatalyst (referred to as Ni(OH) 2 -Ti(IV)/TiO 2 ) were prepared by facile two-step process which was the initial formation of amorphous Ti(IV) on the TiO 2 surface via hydrolysis method and the following formation of Ni(OH) 2 via precipitation reaction. It was found that the Ni(OH) 2 -Ti(IV)/TiO 2 showed obviously high hydrogen-production performance. When the amount of Ni(OH) 2 and Ti(IV) was 1 wt% and 0.1 wt%, respectively, the hydrogen-production rate of the resultant Ni(OH) 2 -Ti(IV)/TiO 2 reached 7280.04 μmol h −1 g −1 , which was significantly higher than that of TiO 2 , Ti(IV)/TiO 2 and Ni(OH) 2 /TiO 2 by a factor of 215, 63 and 1.8, respectively. Moreover, it was found that Ni(OH) 2 -Ti(IV)/TiO 2 photocatalyst preserved a steady and highly efficient H 2 -production performance during repeated tests and also exhibited a high transient photocurrent density. The enhanced hydrogen-production performance of Ni(OH) 2 -Ti(IV)/TiO 2 can be attributed to the synergistic effect of Ti(IV) hole Cocatalyst and Ni(OH) 2 electron Cocatalyst to simultaneously accelerate the interfacial transfer of photogenerated holes and electrons. The present surface modification of dual Cocatalysts can be regarded as one of the ideal strategies for the preparation of highly efficient hydrogen-production materials in view of their abundance, low cost and facile method.
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amorphous molybdenum sulfide as highly efficient electron Cocatalyst for enhanced photocatalytic h2 evolution
Applied Catalysis B-environmental, 2016Co-Authors: Huogen Yu, Ping Wang, Pian Xiao, Jiaguo YuAbstract:Abstract Exploiting novel and high-performance electron-Cocatalysts without noble metallic element is of great significance for photocatalytic H 2 -evolution reaction. Molybdenum sulfide is one of the promising candidates of such electron-Cocatalysts, but its present performance is intrinsically restrained by the scarce active sites of unsaturated S atoms. In this study, amorphous MoS x (a-MoS x ) nanoparticles were directly anchored on the g-C 3 N 4 surface by an adsorption-in situ transformation method with the aim of improving photocatalytic H 2 -evolution activity. It was found that compared with the crystalline molybdenum sulfide (c-MoS 2 ), the a-MoS x Cocatalyst clearly exhibited more unsaturated active S atoms due to its highly irregular arrangement structure. Photocatalytic experimental results suggested that the H 2 -evolution activity of g-C 3 N 4 photocatalyst could be obviously improved by loading a-MoS x Cocatalyst, which is obviously higher than that of unmodified g-C 3 N 4 and c-MoS 2 /g-C 3 N 4 . More importantly, in addition to the g-C 3 N 4 , the amorphous MoS x could also work as the efficient electron Cocatalyst to greatly enhance the photocatalytic performance of conventional H 2 -evolution materials such as TiO 2 (a typical UV-light photocatalyst) and CdS (a typical Vis-light photocatalyst). On the basis of the present results, an electron-Cocatalyst mechanism of amorphous MoS x was proposed to account for the improved photocatalytic H 2 -evolution activity, namely, the amorphous MoS x can provide more unsaturated active S atoms as the efficient active sites to rapidly capture protons from solution, and then promote the direct reduction of H + to H 2 by photogenerated electrons. Considering its low cost and high efficiency, the amorphous MoS x Cocatalyst would have great potential for the development of high-performance photocatalytic materials used in various fields.
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enhanced photoinduced stability and photocatalytic activity of cds by dual amorphous Cocatalysts synergistic effect of ti iv hole Cocatalyst and ni ii electron Cocatalyst
Journal of Physical Chemistry C, 2016Co-Authors: Huogen Yu, Ping Wang, Xiao Huang, Jiaguo YuAbstract:CdS is one of the most well-known and important visible-light photocatalytic materials for water splitting to produce hydrogen energy. Owing to its serious photocorrosion property (poor photoinduced stability), however, CdS photocatalyst can unavoidably be oxidized to form S0 by its photogenerated holes, causing an obviously decreased photocatalytic performance. In this study, to improve the photoinduced stability of CdS photocatalyst, amorphous TiO2 (referred to as Ti(IV)) as a hole Cocatalyst was successfully loaded on the CdS surface to prepare Ti(IV)/CdS photocatalysts. It was found that the resultant Ti(IV)/CdS photocatalyst exhibited an obviously enhanced photocatalytic stability, namely, its deactivation rate clearly decreased from 37.9% to 13.5% after five cycles of photocatalytic reactions. However, its corresponding photocatalytic activity only showed a very limited increase (ca. 37.4%) compared with the naked CdS. To further improve its photocatalytic performance, the amorphous Ni(II) as an ele...
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cu ii as a general Cocatalyst for improved visible light photocatalytic performance of photosensitive ag based compounds
Journal of Physical Chemistry C, 2014Co-Authors: Ping Wang, Panpan Wu, Xuefei Wang, Huogen Yu, Jiaguo YuAbstract:Usually, Cocatalyst modification of photocatalysts is an efficient approach to enhance the photocatalytic performance by promoting effective separation of photogenerated electrons and holes. It is highly required to explore new and effective Cocatalysts to further enhance the photocatalytic performance of photocatalytic materials. In the present work, Cu(II) Cocatalyst was successfully loaded on the surface of various Ag-based compounds (such as AgCl, Ag3PO4, AgBr, AgI, Ag2CO3, and Ag2O) by a simple impregnation route, and their photocatalytic activity of Cu(II)/Ag-based photocatalysts was evaluated by the photocatalytic decolorization of methyl orange and photocatalytic decomposition of phenol solution under visible-light illumination. As one of the typical photosensitive Ag-based compounds, the photocatalytic activity of AgCl could be greatly improved by optimizing the amount of Cu(II) Cocatalyst, and the highest photocatalytic performance of the resulted Cu(II)/AgCl was higher than that of the unmodifi...
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enhanced photoinduced stability and photocatalytic activity of agbr photocatalyst by surface modification of fe iii Cocatalyst
Applied Catalysis B-environmental, 2014Co-Authors: Huogen Yu, Xuefei Wang, Ping Wang, Linli Xu, Jiaguo YuAbstract:Abstract Recently, AgBr material was demonstrated to be a new and efficient visible-light photocatalyst for the decomposition of various organic compounds. Owing to its excellent photosensitive properties, however, AgBr phase is unavoidably decomposed into metallic Ag under visible-light irradiation, resulting in an obvious destroy of its surface structure. In this study, Fe(III) Cocatalyst was grafted on the surface of AgBr particles to form Fe(III)/AgBr photocatalysts by an impregnation method and their photocatalytic performance was evaluated by the photocatalytic decolorization of methyl orange solution under visible-light irradiation. It was found that the Fe(III) cluster could act as a new and effective Cocatalyst not only to improve the photocatalytic activity of AgBr photocatalyst, but also remarkably enhance the photoinduced stability of photosensitive AgBr. After surface coating by Fe(III) Cocatalyst (8.2 at.%), the photocatalytic activity of AgBr photocatalyst can be greatly improved by a factor of 73% even after five cycles of photocatalytic reactions. Simultaneously, the decomposed amount of AgBr can be significantly deduced from 8.8 at.% to 2.9 at.% by the surface loading of Fe(III) Cocatalyst. On the basis of the experimental results, an possible mechanism for the enhanced photocatalytic activity and photoinduced stability of AgBr by Fe(III) Cocatalyst was proposed. Compared with the well-known noble metal Cocatalysts (e.g., Pt, Au, Ag), the present abundant and cheap Fe(III) Cocatalyst can be regarded as one of the ideal Cocatalyst for the smart design and development of high-performance photocatalytic materials in various potential applications.
Kazuhiko Maeda - One of the best experts on this subject based on the ideXlab platform.
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Effect of Hydrogen and Oxygen Evolution Cocatalysts on Photocatalytic Activity of GaN:ZnO
European Journal of Inorganic Chemistry, 2013Co-Authors: Anke Xiong, Kazuhiko Maeda, Takashi Hisatomi, Taizo Yoshinaga, Takahiro Ikeda, Masaki Takashima, Toru Setoyama, Toshiharu Teranishi, Kazunari DomenAbstract:The coloading effect of H2 and O2 evolution Cocatalysts on the overall water splitting reaction was investigated using a solid solution of GaN and ZnO (hereafter termed GaN:ZnO) as a photocatalyst. GaN:ZnO was modified with nanoparticulate Mn3O4, RuO2, and IrO2 as O2 evolution Cocatalysts and with core/shell-type Rh/Cr2O3 composites as H2 evolution Cocatalysts. The photocatalytic activity of the coloaded samples for overall water splitting was higher than that of the samples modified with either of the O2 or H2 evolution Cocatalysts alone. The activity enhancement induced by coloading was comparable for the three O2 evolution Cocatalysts investigated at the optimized loading amounts. Loading of a more efficient Rh/Cr2O3 Cocatalyst prepared by adsorption of Rh nanoparticles further improved the photocatalytic activity. It was concluded that a simultaneous improvement in both oxidation and reduction reactions was effective at enhancing the photocatalytic activity of GaN:ZnO, whereas the reduction reactions limited the overall reaction rate of the coloaded system more significantly.
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photocatalytic water splitting using modified gan zno solid solution under visible light long time operation and regeneration of activity
Journal of the American Chemical Society, 2012Co-Authors: Tomoyuki Ohno, Kazuhiko Maeda, Takashi Hisatomi, Kazunari DomenAbstract:Overall water splitting using GaN:ZnO solid solution photocatalyst modified with Rh2–yCryO3 nanoparticles as H2 evolution Cocatalysts under visible light (400 < λ < 500 nm) was examined with respect to long-term durability and regeneration of photocatalytic activity. The rate of visible light water splitting remained unchanged for 3 months (2160 h), producing H2 and O2 continuously at a stoichiometric amount. After 6 months of operation, a 50% loss of the initial activity occurred. Regeneration treatment of deactivated catalysts was attempted by reloading the Rh2–yCryO3 Cocatalyst. The degree of activity regeneration depended on the reloading amount. Up to 80% of the initial activity for H2 evolution could be recovered under optimal treatment conditions. It was also found that deactivation of GaN:ZnO was suppressed to some extent by prior coloading of an O2 evolution Cocatalyst, which helped to suppress oxidative decomposition of GaN:ZnO by valence band holes, thereby improving the durability.
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photocatalytic water splitting using semiconductor particles history and recent developments
Journal of Photochemistry and Photobiology C-photochemistry Reviews, 2011Co-Authors: Kazuhiko MaedaAbstract:Abstract Overall water splitting to produce H 2 and O 2 over a semiconductor photocatalyst using solar energy is a promising process for the large-scale production of clean, recyclable H 2 . Numerous attempts have been made to develop photocatalysts that function under visible-light irradiation to efficiently utilize solar energy. In general, overall water splitting over a photocatalyst particle can be achieved by modifying the photocatalyst with a suitable Cocatalyst to provide an active redox site. Therefore, the development of active photocatalytic materials has relied on both photocatalysts and Cocatalysts. This review article describes the historical development of water-splitting photocatalysts.
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Photocatalytic water splitting using semiconductor particles: History and recent developments
Journal of Photochemistry and Photobiology C: Photochemistry Reviews, 2011Co-Authors: Kazuhiko MaedaAbstract:Overall water splitting to produce H2and O2over a semiconductor photocatalyst using solar energy is a promising process for the large-scale production of clean, recyclable H2. Numerous attempts have been made to develop photocatalysts that function under visible-light irradiation to efficiently utilize solar energy. In general, overall water splitting over a photocatalyst particle can be achieved by modifying the photocatalyst with a suitable Cocatalyst to provide an active redox site. Therefore, the development of active photocatalytic materials has relied on both photocatalysts and Cocatalysts. This review article describes the historical development of water-splitting photocatalysts. © 2011 Elsevier B.V.
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photocatalytic water splitting recent progress and future challenges
Journal of Physical Chemistry Letters, 2010Co-Authors: Kazuhiko Maeda, Kazunari DomenAbstract:Water splitting to form hydrogen and oxygen using solar energy in the presence of semiconductor photocatalysts has long been studied as a potential means of clean, large-scale fuel production. In general, overall water splitting can be achieved when a photocatalyst is modified with a suitable Cocatalyst. It is therefore important to develop both photocatalysts and Cocatalysts. In the past five years, there has been significant progress in water splitting photocatalysis, especially in the development of Cocatalysts and related physical and materials chemistry. This work describes the state of the art and future challenges in photocatalytic water splitting, with a focus on the recent progress of our own research.
Ping Wang - One of the best experts on this subject based on the ideXlab platform.
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co modification of amorphous ti iv hole Cocatalyst and ni oh 2 electron Cocatalyst for enhanced photocatalytic h2 production performance of tio2
Applied Surface Science, 2017Co-Authors: Ping Wang, Xuefei Wang, Yanggang Lu, Huogen YuAbstract:Abstract Highly efficient TiO 2 photocatalysts co-modified by amorphous-Ti(IV) hole Cocatalyst and Ni(OH) 2 electron Cocatalyst (referred to as Ni(OH) 2 -Ti(IV)/TiO 2 ) were prepared by facile two-step process which was the initial formation of amorphous Ti(IV) on the TiO 2 surface via hydrolysis method and the following formation of Ni(OH) 2 via precipitation reaction. It was found that the Ni(OH) 2 -Ti(IV)/TiO 2 showed obviously high hydrogen-production performance. When the amount of Ni(OH) 2 and Ti(IV) was 1 wt% and 0.1 wt%, respectively, the hydrogen-production rate of the resultant Ni(OH) 2 -Ti(IV)/TiO 2 reached 7280.04 μmol h −1 g −1 , which was significantly higher than that of TiO 2 , Ti(IV)/TiO 2 and Ni(OH) 2 /TiO 2 by a factor of 215, 63 and 1.8, respectively. Moreover, it was found that Ni(OH) 2 -Ti(IV)/TiO 2 photocatalyst preserved a steady and highly efficient H 2 -production performance during repeated tests and also exhibited a high transient photocurrent density. The enhanced hydrogen-production performance of Ni(OH) 2 -Ti(IV)/TiO 2 can be attributed to the synergistic effect of Ti(IV) hole Cocatalyst and Ni(OH) 2 electron Cocatalyst to simultaneously accelerate the interfacial transfer of photogenerated holes and electrons. The present surface modification of dual Cocatalysts can be regarded as one of the ideal strategies for the preparation of highly efficient hydrogen-production materials in view of their abundance, low cost and facile method.
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amorphous molybdenum sulfide as highly efficient electron Cocatalyst for enhanced photocatalytic h2 evolution
Applied Catalysis B-environmental, 2016Co-Authors: Huogen Yu, Ping Wang, Pian Xiao, Jiaguo YuAbstract:Abstract Exploiting novel and high-performance electron-Cocatalysts without noble metallic element is of great significance for photocatalytic H 2 -evolution reaction. Molybdenum sulfide is one of the promising candidates of such electron-Cocatalysts, but its present performance is intrinsically restrained by the scarce active sites of unsaturated S atoms. In this study, amorphous MoS x (a-MoS x ) nanoparticles were directly anchored on the g-C 3 N 4 surface by an adsorption-in situ transformation method with the aim of improving photocatalytic H 2 -evolution activity. It was found that compared with the crystalline molybdenum sulfide (c-MoS 2 ), the a-MoS x Cocatalyst clearly exhibited more unsaturated active S atoms due to its highly irregular arrangement structure. Photocatalytic experimental results suggested that the H 2 -evolution activity of g-C 3 N 4 photocatalyst could be obviously improved by loading a-MoS x Cocatalyst, which is obviously higher than that of unmodified g-C 3 N 4 and c-MoS 2 /g-C 3 N 4 . More importantly, in addition to the g-C 3 N 4 , the amorphous MoS x could also work as the efficient electron Cocatalyst to greatly enhance the photocatalytic performance of conventional H 2 -evolution materials such as TiO 2 (a typical UV-light photocatalyst) and CdS (a typical Vis-light photocatalyst). On the basis of the present results, an electron-Cocatalyst mechanism of amorphous MoS x was proposed to account for the improved photocatalytic H 2 -evolution activity, namely, the amorphous MoS x can provide more unsaturated active S atoms as the efficient active sites to rapidly capture protons from solution, and then promote the direct reduction of H + to H 2 by photogenerated electrons. Considering its low cost and high efficiency, the amorphous MoS x Cocatalyst would have great potential for the development of high-performance photocatalytic materials used in various fields.
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enhanced photoinduced stability and photocatalytic activity of cds by dual amorphous Cocatalysts synergistic effect of ti iv hole Cocatalyst and ni ii electron Cocatalyst
Journal of Physical Chemistry C, 2016Co-Authors: Huogen Yu, Ping Wang, Xiao Huang, Jiaguo YuAbstract:CdS is one of the most well-known and important visible-light photocatalytic materials for water splitting to produce hydrogen energy. Owing to its serious photocorrosion property (poor photoinduced stability), however, CdS photocatalyst can unavoidably be oxidized to form S0 by its photogenerated holes, causing an obviously decreased photocatalytic performance. In this study, to improve the photoinduced stability of CdS photocatalyst, amorphous TiO2 (referred to as Ti(IV)) as a hole Cocatalyst was successfully loaded on the CdS surface to prepare Ti(IV)/CdS photocatalysts. It was found that the resultant Ti(IV)/CdS photocatalyst exhibited an obviously enhanced photocatalytic stability, namely, its deactivation rate clearly decreased from 37.9% to 13.5% after five cycles of photocatalytic reactions. However, its corresponding photocatalytic activity only showed a very limited increase (ca. 37.4%) compared with the naked CdS. To further improve its photocatalytic performance, the amorphous Ni(II) as an ele...
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cu ii as a general Cocatalyst for improved visible light photocatalytic performance of photosensitive ag based compounds
Journal of Physical Chemistry C, 2014Co-Authors: Ping Wang, Panpan Wu, Xuefei Wang, Huogen Yu, Jiaguo YuAbstract:Usually, Cocatalyst modification of photocatalysts is an efficient approach to enhance the photocatalytic performance by promoting effective separation of photogenerated electrons and holes. It is highly required to explore new and effective Cocatalysts to further enhance the photocatalytic performance of photocatalytic materials. In the present work, Cu(II) Cocatalyst was successfully loaded on the surface of various Ag-based compounds (such as AgCl, Ag3PO4, AgBr, AgI, Ag2CO3, and Ag2O) by a simple impregnation route, and their photocatalytic activity of Cu(II)/Ag-based photocatalysts was evaluated by the photocatalytic decolorization of methyl orange and photocatalytic decomposition of phenol solution under visible-light illumination. As one of the typical photosensitive Ag-based compounds, the photocatalytic activity of AgCl could be greatly improved by optimizing the amount of Cu(II) Cocatalyst, and the highest photocatalytic performance of the resulted Cu(II)/AgCl was higher than that of the unmodifi...
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enhanced photoinduced stability and photocatalytic activity of agbr photocatalyst by surface modification of fe iii Cocatalyst
Applied Catalysis B-environmental, 2014Co-Authors: Huogen Yu, Xuefei Wang, Ping Wang, Linli Xu, Jiaguo YuAbstract:Abstract Recently, AgBr material was demonstrated to be a new and efficient visible-light photocatalyst for the decomposition of various organic compounds. Owing to its excellent photosensitive properties, however, AgBr phase is unavoidably decomposed into metallic Ag under visible-light irradiation, resulting in an obvious destroy of its surface structure. In this study, Fe(III) Cocatalyst was grafted on the surface of AgBr particles to form Fe(III)/AgBr photocatalysts by an impregnation method and their photocatalytic performance was evaluated by the photocatalytic decolorization of methyl orange solution under visible-light irradiation. It was found that the Fe(III) cluster could act as a new and effective Cocatalyst not only to improve the photocatalytic activity of AgBr photocatalyst, but also remarkably enhance the photoinduced stability of photosensitive AgBr. After surface coating by Fe(III) Cocatalyst (8.2 at.%), the photocatalytic activity of AgBr photocatalyst can be greatly improved by a factor of 73% even after five cycles of photocatalytic reactions. Simultaneously, the decomposed amount of AgBr can be significantly deduced from 8.8 at.% to 2.9 at.% by the surface loading of Fe(III) Cocatalyst. On the basis of the experimental results, an possible mechanism for the enhanced photocatalytic activity and photoinduced stability of AgBr by Fe(III) Cocatalyst was proposed. Compared with the well-known noble metal Cocatalysts (e.g., Pt, Au, Ag), the present abundant and cheap Fe(III) Cocatalyst can be regarded as one of the ideal Cocatalyst for the smart design and development of high-performance photocatalytic materials in various potential applications.
