The Experts below are selected from a list of 68445 Experts worldwide ranked by ideXlab platform
Kazunari Domen - One of the best experts on this subject based on the ideXlab platform.
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Recent developments in heterogeneous photocatalysts for solar-driven overall water splitting
Chemical Society Reviews, 2019Co-Authors: Zheng Wang, Kazunari DomenAbstract:Overall water splitting based on particulate photocatalysts is an easily constructed and cost-effective technology for the conversion of abundant solar energy into clean and renewable hydrogen energy on a large scale. This promising technology can be achieved in a one-step excitation system using a single photocatalyst or via a Z-scheme process based on a pair of photocatalysts. Ideally, such Photocatalysis will proceed with charge separation and transport unaffected by recombination and trapping, and surface catalytic processes will not involve undesirable reactions. This review summarizes the basics of overall water splitting via both one-step excitation and Z-scheme processes, with a focus on standard methods of determining photocatalytic performance. Various surface engineering strategies applied to photocatalysts, such as cocatalyst loading, surface morphology control, surface modification and surface phase junctions, have been developed to allow efficient one-step excitation overall water splitting. In addition, numerous visible-light-responsive photocatalysts have been successfully utilized as H2-evolution or O2-evolution photocatalysts in Z-scheme overall water splitting. Prototype particulate immobilization systems with photocatalytic performances comparable to or drastically higher than those of particle suspension systems suggest the exciting possibility of the large-scale production of low-cost renewable solar hydrogen.
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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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ruo2 loaded β ge3n4 as a non oxide photocatalyst for overall water splitting
Journal of the American Chemical Society, 2005Co-Authors: Junya Sato, Kazuhiko Maeda, Kazunari Domen, Nobuo Saito, Yoko Yamada, Tsuyoshi Takata, Junko N Kondo, Michikazu Hara, Hisayoshi Kobayashi, Yasunobu InoueAbstract:Germanium nitride β-Ge3N4 dispersed with RuO2 nanoparticles is presented as the first example of a non-oxide photocatalyst for the stoichiometric decomposition of H2O into H2 and O2. All of the successful photocatalysts developed for overall water splitting over the past 30 years have been based on oxides of metals. The discovery of a non-oxide photocatalyst, such as nitrides and oxynitrides, achieving the same function is therefore expected to stimulate research on non-oxide photocatalysts. New opportunities for progress in the development of visible light-driven Photocatalysis can thus be expected, as the higher valence band positions of metal nitrides compared to the corresponding metal oxides provide narrower band gaps, which are suitable for visible light activity.
Lizhi Zhang - One of the best experts on this subject based on the ideXlab platform.
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oxygen vacancy mediated Photocatalysis of biocl reactivity selectivity and perspectives
Angewandte Chemie, 2018Co-Authors: Hao Li, Jie Li, Zhihui Ai, Falong Jia, Lizhi ZhangAbstract:Semiconductor Photocatalysis is a trustworthy approach to harvest clean solar light for energy conversions, while state-of-the-art catalytic efficiencies are unsatisfactory because of the finite light response and/or robust charge carriers' recombination. Along with the development of modern material characterization techniques and electronic-structure computations, oxygen vacancies (OVs) on real photocatalysts surface, even in infinitesimal concentration, are found to play a more decisive role in determining the kinetics, energetics and mechanisms of photocatalytic reactions. This review endeavors to clarify the inherent functionality of OVs in Photocatalysis at the surface molecular level using 2D BiOCl as the platform. Structure sensitivity of OVs on reactivity and selectivity of photocatalytic reactions is intensely discussed via confining OVs onto prototypical BiOCl surfaces of different structures. The critical understanding of OVs chemistry in this review can help to consolidate and advance the fundamental theories of Photocatalysis, and also offer new perspectives and guidelines for the rational design of catalysts with satisfactory performance.
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oxygen vacancy mediated Photocatalysis of biocl reactivity selectivity and perspectives
Angewandte Chemie, 2018Co-Authors: Falong Jia, Lizhi ZhangAbstract:Semiconductor Photocatalysis is a trustworthy approach to harvest clean solar light for energy conversions, while state-of-the-art catalytic efficiencies are unsatisfactory because of the finite light response and/or recombination of robust charge carriers. Along with the development of modern material characterization techniques and electronic-structure computations, oxygen vacancies (OVs) on the surface of real photocatalysts, even in infinitesimal concentration, are found to play a more decisive role in determining the kinetics, energetics, and mechanisms of photocatalytic reactions. This Review endeavors to clarify the inherent functionality of OVs in Photocatalysis at the surface molecular level using 2D BiOCl as the platform. Structure sensitivity of OVs on reactivity and selectivity of photocatalytic reactions is intensely discussed via confining OVs onto prototypical BiOCl surfaces of different structures. The critical understanding of OVs chemistry can help consolidate and advance the fundamental theories of Photocatalysis, and also offer new perspectives and guidelines for the rational design of catalysts with satisfactory performance.
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bismuth oxyhalide nanomaterials layered structures meet Photocatalysis
Nanoscale, 2014Co-Authors: Jie Li, Ying Yu, Lizhi ZhangAbstract:In recent years, layered bismuth oxyhalide nanomaterials have received more and more interest as promising photocatalysts because their unique layered structures endow them with fascinating physicochemical properties; thus, they have great potential photocatalytic applications for environment remediation and energy harvesting. In this article, we explore the synthesis strategies and growth mechanisms of layered bismuth oxyhalide nanomaterials, and propose design principles of tailoring a layered configuration to control the nanoarchitectures for high efficient Photocatalysis. Subsequently, we focus on their layered structure dependent properties, including pH-related crystal facet exposure and phase transformation, facet-dependent photoactivity and molecular oxygen activation pathways, so as to clarify the origin of the layered structure dependent photoreactivity. Furthermore, we summarize various strategies for modulating the composition and arrangement of layered structures to enhance the photoactivity of nanostructured bismuth oxyhalides via internal electric field tuning, dehalogenation effect, surface functionalization, doping, plasmon modification, and heterojunction construction, which may offer efficient guidance for the design and construction of high-performance bismuth oxyhalide-based Photocatalysis systems. Finally, we highlight some crucial issues in engineering the layered-structure mediated properties of bismuth oxyhalide photocatalysts and provide tentative suggestions for future research on increasing their photocatalytic performance.
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selective oxidation of benzyl alcohol into benzaldehyde over semiconductors under visible light the case of bi12o17cl2 nanobelts
Applied Catalysis B-environmental, 2013Co-Authors: Xiaoyi Xiao, Jing Jiang, Lizhi ZhangAbstract:Abstract In this study we propose several criteria for semiconductor photocatalysts suitable for visible light driven selective oxidation of BA to BAD by employing several literature-reported photocatalysts (P25, g-C 3 N 4 , In(OH) x S y , Bi 3 O 4 Br, BiOBr and Cu 2 O) to oxidize BA under visible light, and then demonstrate that the selectivity of photocatalytic oxidation of benzyl alcohol is highly depended on the position of valence band of semiconductors and Bi 12 O 17 Cl 2 nanobelts could efficiently and selectively oxidize benzyl alcohol into benzaldehyde under visible light via direct hole oxidation. Although the presence of molecular oxygen and the generation of superoxide radicals are important for the selective oxidation of benzyl alcohol, the exact role of molecular oxygen is merely to trap photogenerated electrons to produce superoxide radicals during Bi 12 O 17 Cl 2 Photocatalysis, which could inhibit the recombination of photogenerated charge carries, but might not be involved in the alcohol oxidation directly. The role of molecular oxygen during Bi 12 O 17 Cl 2 Photocatalysis was found to be different from those of TiO 2 and g-C 3 N 4 previously reported. This study provides new physical insights for the roles of active species during selective oxidation of alcohol under visible light and the design of novel visible light active photocatalysts for selective oxidation of alcohol.
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new insight into daylight Photocatalysis of agbr ag synergistic effect between semiconductor Photocatalysis and plasmonic Photocatalysis
Chemistry: A European Journal, 2012Co-Authors: Jing Jiang, Lizhi ZhangAbstract:Noble metal nanoparticles (NPs) are often used as electron scavengers in conventional semiconductor Photocatalysis to suppress electron-hole (e(-)-h(+) ) recombination and promote interfacial charge transfer, and thus enhance photocatalytic activity of semiconductors. In this contribution, it is demonstrated that noble metal NPs such as Ag NPs function as visible-light harvesting and electron-generating centers during the daylight Photocatalysis of AgBr@Ag. Novel Ag plasmonic Photocatalysis could cooperate with the conventional AgBr semiconductor Photocatalysis to enhance the overall daylight activity of AgBr@Ag greatly because of an interesting synergistic effect. After a systematic investigation of the daylight Photocatalysis mechanism of AgBr@Ag, the synergistic effect was attributed to surface plasmon resonance induced local electric field enhancement on Ag, which can accelerate the generation of e(-)-h(+) pairs in AgBr, so that more electrons are produced in the conduction band of AgBr under daylight irradiation. This study provides new insight into the photocatalytic mechanism of noble metal/semiconductor systems as well as the design and fabrication of novel plasmonic photocatalysts.
Ghim Wei Ho - One of the best experts on this subject based on the ideXlab platform.
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Harvesting broadband absorption of the solar spectrum for enhanced photocatalytic H2 generation
Journal of Materials Chemistry, 2015Co-Authors: Ghim Wei HoAbstract:Absorption of the solar spectrum in the visible and near infrared region is highly desirable to improve photocatalytic H2 generation. Traditionally, this can be fulfilled by designing photocatalyst materials with narrower band gaps, or with upconversion capabilities. However, such materials often pose challenges such as in synthesis, structural defects, and stability which may lead to adverse photocatalytic performance. This paper focuses on broadband utilization of the solar spectrum for enhanced Photocatalysis solar H2 production where the spectrum not utilized by the photocatalysts is absorbed and converted to heat energy. This approach delves into harvesting the broadband spectrum for synergistic Photocatalysis and thermal heat generation, with minimal photocatalyst material manipulation. The profound impact of temperature on Photocatalysis was manifested in a drastic increase of H2 production by a maximum of 40-fold. The apparent quantum yield was also calculated to reach 66.9% using an ultraviolet LED light source. Outdoor testing verifies the potential of broad spectrum operation under natural sunlight as well as the convenience and simplicity of various reactor designs for practical Photocatalysis applications.
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structural design of tio2 based photocatalyst for h2 production and degradation applications
Catalysis Science & Technology, 2015Co-Authors: Jing Wang, Ghim Wei HoAbstract:TiO2-based photocatalysts, being inexpensive and abundant, in conjunction with having high photostability and environmentally friendly characteristics, are the most extensively studied photocatalytic material for hydrogen production and pollutant degradation. However, its existing issues, such as wide bandgap, high overpotential and rapid recombination of photogenerated carriers limit its photocatalytic properties. The opportunities for structural development of a TiO2 nanomaterial towards highly efficient and pragmatic Photocatalysis applications are evidently plentiful. Hence, in this review, we will look into critical structural engineering strategies that give favorable physicochemical properties such as improved light absorption, photostability, charge-carrier dynamics, increase surface area etc. that benefit Photocatalysis functionalities. Amongst the various structural engineering options, we will be covering the most prevalent and elegant core–shell and hierarchical structural designs, which rationally combine the advantages of structural manipulation and multi-material composition engineering. This review aims to provide a comprehensive and contemporary overview, as well as a guide of the development of new generation TiO2 based photocatalysts via structural design for improved solar energy conversion technologies.
Sumet Sakulsermsuk - One of the best experts on this subject based on the ideXlab platform.
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an overview of solar visible light driven heterogeneous Photocatalysis for water purification tio2 and zno based photocatalysts used in suspension photoreactors
Journal of Industrial and Engineering Chemistry, 2019Co-Authors: Khatcharin Wetchakun, Natda Wetchakun, Sumet SakulsermsukAbstract:Abstract Heterogeneous photocatalysts are able to be prepared with various methods and are allowed to modify to improve photocatalytic efficiency. In this review, we evaluate current researches on (I) the development of TiO2- and ZnO-based photocatalysts made through hydrothermal, sol–gel and flame spray pyrolysis processes, and (II) the development of suspension photoreactors with practical parameters influencing to photocatalytic activity. In both development approaches, the studies achieving the optimum of Photocatalysis performance in high-yield degradation with associated parameters are explored, and the main causes of enhanced efficiency are described. Finally, from our view, opportunities for improvement on heterogeneous photocatalysts for water treatment are addressed.
Kazuhiko Maeda - One of the best experts on this subject based on the ideXlab platform.
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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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ruo2 loaded β ge3n4 as a non oxide photocatalyst for overall water splitting
Journal of the American Chemical Society, 2005Co-Authors: Junya Sato, Kazuhiko Maeda, Kazunari Domen, Nobuo Saito, Yoko Yamada, Tsuyoshi Takata, Junko N Kondo, Michikazu Hara, Hisayoshi Kobayashi, Yasunobu InoueAbstract:Germanium nitride β-Ge3N4 dispersed with RuO2 nanoparticles is presented as the first example of a non-oxide photocatalyst for the stoichiometric decomposition of H2O into H2 and O2. All of the successful photocatalysts developed for overall water splitting over the past 30 years have been based on oxides of metals. The discovery of a non-oxide photocatalyst, such as nitrides and oxynitrides, achieving the same function is therefore expected to stimulate research on non-oxide photocatalysts. New opportunities for progress in the development of visible light-driven Photocatalysis can thus be expected, as the higher valence band positions of metal nitrides compared to the corresponding metal oxides provide narrower band gaps, which are suitable for visible light activity.
