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Kazunari Domen - One of the best experts on this subject based on the ideXlab platform.
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Photocatalytic Water Splitting with a quantum efficiency of almost unity
Nature, 2020Co-Authors: Tsuyoshi Takata, Takashi Hisatomi, Junzhe Jiang, Yoshihisa Sakata, Mamiko Nakabayashi, Naoya Shibata, Vikas Nandal, Kazuhiko Seki, Kazunari DomenAbstract:Overall Water Splitting, evolving hydrogen and oxygen in a 2:1 stoichiometric ratio, using particulate photocatalysts is a potential means of achieving scalable and economically viable solar hydrogen production. To obtain high solar energy conversion efficiency, the quantum efficiency of the photocatalytic reaction must be increased over a wide range of wavelengths and semiconductors with narrow bandgaps need to be designed. However, the quantum efficiency associated with overall Water Splitting using existing photocatalysts is typically lower than ten per cent1,2. Thus, whether a particulate photocatalyst can enable a quantum efficiency of 100 per cent for the greatly endergonic Water-Splitting reaction remains an open question. Here we demonstrate overall Water Splitting at an external quantum efficiency of up to 96 per cent at wavelengths between 350 and 360 nanometres, which is equivalent to an internal quantum efficiency of almost unity, using a modified aluminium-doped strontium titanate (SrTiO3:Al) photocatalyst3,4. By selectively photodepositing the cocatalysts Rh/Cr2O3 (ref. 5) and CoOOH (refs. 3,6) for the hydrogen and oxygen evolution reactions, respectively, on different crystal facets of the semiconductor particles using anisotropic charge transport, the hydrogen and oxygen evolution reactions could be promoted separately. This enabled multiple consecutive forward charge transfers without backward charge transfer, reaching the upper limit of quantum efficiency for overall Water Splitting. Our work demonstrates the feasibility of overall Water Splitting free from charge recombination losses and introduces an ideal cocatalyst/photocatalyst structure for efficient Water Splitting. Water Splitting with an internal quantum efficiency of almost unity is achieved using a modified semiconductor photocatalyst that selectively promotes the hydrogen and oxygen evolution reactions on separate crystal facets.
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Visible-Light-Driven Photocatalytic Water Splitting: Recent Progress and Challenges
Trends in Chemistry, 2020Co-Authors: Lihua Lin, Takashi Hisatomi, Tsuyoshi Takata, Shanshan Chen, Kazunari DomenAbstract:Sunlight-driven photocatalytic Water Splitting is one of the most promising approaches to generating renewable hydrogen as an energy source. In recent years, significant progress has been made in the development of photocatalytic Water-Splitting systems. Among these, the one- and two-step-excitation overall Water-Splitting processes are most widely investigated. Realization of visible-light-driven overall Water Splitting is one of the most important goals at present because of the need to obtain systems exhibiting high solar-to-hydrogen energy conversion efficiency for practical applications. The present review focuses on recent progress in the field of photocatalytic Water Splitting, especially in the research and design of visible-light-driven overall Water-Splitting systems, and outlines potential strategies to overcome the difficulties related to practical applications.
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particulate photocatalysts for overall Water Splitting
Nature Reviews Materials, 2017Co-Authors: Shanshan Chen, Tsuyoshi Takata, Kazunari DomenAbstract:Overall Water Splitting using powdered photocatalysts is a promising approach to large-scale solar hydrogen production. This Review details recent developments in particulate photocatalysts for overall Water Splitting based on one- and two-step photoexcitation systems.
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Particulate photocatalysts for overall Water Splitting
Nature Reviews Materials, 2017Co-Authors: Shanshan Chen, Tsuyoshi Takata, Kazunari DomenAbstract:Overall Water Splitting using powdered photocatalysts is a promising approach to large-scale solar hydrogen production. This Review details recent developments in particulate photocatalysts for overall Water Splitting based on one- and two-step photoexcitation systems. The conversion of solar energy to chemical energy is a promising way of generating renewable energy. Hydrogen production by means of Water Splitting over semiconductor photocatalysts is a simple, cost-effective approach to large-scale solar hydrogen synthesis. Since the discovery of the Honda–Fujishima effect, considerable progress has been made in this field, and numerous photocatalytic materials and Water-Splitting systems have been developed. In this Review, we summarize existing Water-Splitting systems based on particulate photocatalysts, focusing on the main components: light-harvesting semiconductors and co-catalysts. The essential design principles of the materials employed for overall Water-Splitting systems based on one-step and two-step photoexcitation are also discussed, concentrating on three elementary processes: photoabsorption, charge transfer and surface catalytic reactions. Finally, we outline challenges and potential advances associated with solar Water Splitting by particulate photocatalysts for future commercial applications.
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Solar hydrogen production on some Water Splitting photocatalysts
Solar Hydrogen and Nanotechnology XI, 2016Co-Authors: Tsuyoshi Takata, Takashi Hisatomi, Kazunari DomenAbstract:Photocatalytic overall Water Splitting into H2 and O2 is expected to be a promising method for the efficient utilization of solar energy. The design of optimal photocatalyst structures is a key to efficient overall Water Splitting, and the development of photocatalysts which can efficiently convert large portion of visible light spectrum has been required. Recently, a series of complex perovskite type transition metal oxynitrides, LaMgxT 1-xO1+3xN2-3x, was developed as photocatalysts for direct Water Splitting operable at wide wavelength of visible light. In addition two-step excitation Water Splitting via a novel photocatalytic device termed as photocatalyst sheet was developed. This consists of two types of semiconductors (hydrogen evolution photocatalyst and oxygen evolution photocatalyst) particles embedded in a conductive layer, and showed high efficiency for overall Water Splitting. These recent advances in photocatalytic Water Splitting were introduced.
Kazuhiko Maeda - One of the best experts on this subject based on the ideXlab platform.
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Water Splitting on Rutile TiO2 -Based Photocatalysts.
Chemistry (Weinheim an der Bergstrasse Germany), 2018Co-Authors: Akinobu Miyoshi, Shunta Nishioka, Kazuhiko MaedaAbstract:Water Splitting using a semiconductor photocatalyst with sunlight has long been viewed as a potential means of large-scale H2 production from renewable resources. Different from anatase TiO2 , rutile enables preferential Water oxidation, which is useful for the construction of a Z-scheme Water-Splitting system. The combination of rutile TiO2 with a suitable H2 -evolution photocatalyst such as a Pt-loaded BaZrO3 -BaTaO2 N solid solution enables solar-driven Water Splitting into H2 and O2 . While rutile TiO2 is a wide-gap semiconductor with a bandgap of 3.0 eV, co-doping of rutile TiO2 with certain metal ions and/or nitrogen produces visible-light-driven photocatalysts, which are also useful as a component for Water oxidation in visible-light-driven Z-scheme Water Splitting. The key to achieving highly efficient Water oxidation is to maintain a charge balance of dopants in the rutile, because single doping typically produces trap states that capture photogenerated electrons and/or holes. Here we provide a concise summary of rutile TiO2 -based photocatalysts for Water-Splitting systems.
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z scheme Water Splitting using two different semiconductor photocatalysts
ACS Catalysis, 2013Co-Authors: Kazuhiko MaedaAbstract:Water Splitting on illuminated semiconductors has long been studied as a potential means of converting solar energy into chemical energy in the form of H2, a clean and renewable energy carrier. Photocatalytic Water Splitting through two-step photoexcitation using two different semiconductor powders and a reversible donor/acceptor pair (so-called shuttle redox mediator) is one of the possible forms of artificial photosynthesis. This system was inspired by natural photosynthesis in green plants and is called the “Z-scheme”. The development of Z-scheme Water Splitting systems has relied on both finding a new semiconductor photocatalyst that efficiently works in the presence of a shuttle redox mediator and creating active sites to promote surface chemical reactions while suppressing backward reactions involving redox mediators. This review article describes the historical development of photocatalytic Water Splitting systems driven by the Z-scheme principle.
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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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Oxynitride materials for solar Water Splitting.
MRS Bulletin, 2011Co-Authors: Kazuhiko Maeda, Kazunari DomenAbstract:Water Splitting to form hydrogen and oxygen over a heterogeneous photocatalyst using solar energy is a promising process for clean and renewable hydrogen production. In recent years, numerous attempts have been made for the development of photocatalysts that work under visible light irradiation to efficiently utilize solar energy. This article reviews recent research progress in the development of visible light-driven photocatalysts, focusing on the refinement of oxynitride materials. They harvest visible photons (~450–700 nm) and work as stable photocatalysts for Water reduction and oxidation under visible light. Oxynitrides with d 0 electronic configuration can be successfully applied to a two-step Water-Splitting system, which can harvest a wide range of visible photons (~660 nm), in the presence of an iodate/iodide shuttle redox mediator. Also d 10 -type oxynitrides of GaN–ZnO and ZnGeN 2 –ZnO solid solutions can achieve functionality as photocatalysts for overall Water-Splitting under visible light without noticeable degradation.
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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.
Takashi Hisatomi - One of the best experts on this subject based on the ideXlab platform.
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Photocatalytic Water Splitting with a quantum efficiency of almost unity
Nature, 2020Co-Authors: Tsuyoshi Takata, Takashi Hisatomi, Junzhe Jiang, Yoshihisa Sakata, Mamiko Nakabayashi, Naoya Shibata, Vikas Nandal, Kazuhiko Seki, Kazunari DomenAbstract:Overall Water Splitting, evolving hydrogen and oxygen in a 2:1 stoichiometric ratio, using particulate photocatalysts is a potential means of achieving scalable and economically viable solar hydrogen production. To obtain high solar energy conversion efficiency, the quantum efficiency of the photocatalytic reaction must be increased over a wide range of wavelengths and semiconductors with narrow bandgaps need to be designed. However, the quantum efficiency associated with overall Water Splitting using existing photocatalysts is typically lower than ten per cent1,2. Thus, whether a particulate photocatalyst can enable a quantum efficiency of 100 per cent for the greatly endergonic Water-Splitting reaction remains an open question. Here we demonstrate overall Water Splitting at an external quantum efficiency of up to 96 per cent at wavelengths between 350 and 360 nanometres, which is equivalent to an internal quantum efficiency of almost unity, using a modified aluminium-doped strontium titanate (SrTiO3:Al) photocatalyst3,4. By selectively photodepositing the cocatalysts Rh/Cr2O3 (ref. 5) and CoOOH (refs. 3,6) for the hydrogen and oxygen evolution reactions, respectively, on different crystal facets of the semiconductor particles using anisotropic charge transport, the hydrogen and oxygen evolution reactions could be promoted separately. This enabled multiple consecutive forward charge transfers without backward charge transfer, reaching the upper limit of quantum efficiency for overall Water Splitting. Our work demonstrates the feasibility of overall Water Splitting free from charge recombination losses and introduces an ideal cocatalyst/photocatalyst structure for efficient Water Splitting. Water Splitting with an internal quantum efficiency of almost unity is achieved using a modified semiconductor photocatalyst that selectively promotes the hydrogen and oxygen evolution reactions on separate crystal facets.
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Visible-Light-Driven Photocatalytic Water Splitting: Recent Progress and Challenges
Trends in Chemistry, 2020Co-Authors: Lihua Lin, Takashi Hisatomi, Tsuyoshi Takata, Shanshan Chen, Kazunari DomenAbstract:Sunlight-driven photocatalytic Water Splitting is one of the most promising approaches to generating renewable hydrogen as an energy source. In recent years, significant progress has been made in the development of photocatalytic Water-Splitting systems. Among these, the one- and two-step-excitation overall Water-Splitting processes are most widely investigated. Realization of visible-light-driven overall Water Splitting is one of the most important goals at present because of the need to obtain systems exhibiting high solar-to-hydrogen energy conversion efficiency for practical applications. The present review focuses on recent progress in the field of photocatalytic Water Splitting, especially in the research and design of visible-light-driven overall Water-Splitting systems, and outlines potential strategies to overcome the difficulties related to practical applications.
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Solar hydrogen production on some Water Splitting photocatalysts
Solar Hydrogen and Nanotechnology XI, 2016Co-Authors: Tsuyoshi Takata, Takashi Hisatomi, Kazunari DomenAbstract:Photocatalytic overall Water Splitting into H2 and O2 is expected to be a promising method for the efficient utilization of solar energy. The design of optimal photocatalyst structures is a key to efficient overall Water Splitting, and the development of photocatalysts which can efficiently convert large portion of visible light spectrum has been required. Recently, a series of complex perovskite type transition metal oxynitrides, LaMgxT 1-xO1+3xN2-3x, was developed as photocatalysts for direct Water Splitting operable at wide wavelength of visible light. In addition two-step excitation Water Splitting via a novel photocatalytic device termed as photocatalyst sheet was developed. This consists of two types of semiconductors (hydrogen evolution photocatalyst and oxygen evolution photocatalyst) particles embedded in a conductive layer, and showed high efficiency for overall Water Splitting. These recent advances in photocatalytic Water Splitting were introduced.
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photocatalytic Water Splitting reaction from catalytic and kinetic perspectives
Catalysis Letters, 2015Co-Authors: Takashi Hisatomi, Kazuhiro Takanabe, Kazunari DomenAbstract:Some particulate semiconductors loaded with nanoparticulate catalysts exhibit photocatalytic activity for the Water-Splitting reaction. The photocatalysis is distinct from the thermal catalysis because photocatalysis involves photophysical processes in particulate semiconductors. This review article presents a brief introduction to photocatalysis, followed by kinetic aspects of the photocatalytic Water-Splitting reaction.
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Recent advances in semiconductors for photocatalytic and photoelectrochemical Water Splitting
Chemical Society Reviews, 2014Co-Authors: Takashi Hisatomi, Jun Kubota, Kazunari DomenAbstract:Photocatalytic and photoelectrochemical Water Splitting under irradiation by sunlight has received much attention for production of renewable hydrogen from Water on a large scale. Many challenges still remain in improving energy conversion efficiency, such as utilizing longer-wavelength photons for hydrogen production, enhancing the reaction efficiency at any given wavelength, and increasing the lifetime of the semiconductor materials. This introductory review covers the fundamental aspects of photocatalytic and photoelectrochemical Water Splitting. Controlling the semiconducting properties of photocatalysts and photoelectrode materials is the primary concern in developing materials for solar Water Splitting, because they determine how much photoexcitation occurs in a semiconductor under solar illumination and how many photoexcited carriers reach the surface where Water Splitting takes place. Given a specific semiconductor material, surface modifications are important not only to activate the semiconductor for Water Splitting but also to facilitate charge separation and to upgrade the stability of the material under photoexcitation. In addition, reducing resistance loss and forming p–n junction have a significant impact on the efficiency of photoelectrochemical Water Splitting. Correct evaluation of the photocatalytic and photoelectrochemical activity for Water Splitting is becoming more important in enabling an accurate comparison of a number of studies based on different systems. In the latter part, recent advances in the Water Splitting reaction under visible light will be presented with a focus on non-oxide semiconductor materials to give an overview of the various problems and solutions.
Tsuyoshi Takata - One of the best experts on this subject based on the ideXlab platform.
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Photocatalytic Water Splitting with a quantum efficiency of almost unity
Nature, 2020Co-Authors: Tsuyoshi Takata, Takashi Hisatomi, Junzhe Jiang, Yoshihisa Sakata, Mamiko Nakabayashi, Naoya Shibata, Vikas Nandal, Kazuhiko Seki, Kazunari DomenAbstract:Overall Water Splitting, evolving hydrogen and oxygen in a 2:1 stoichiometric ratio, using particulate photocatalysts is a potential means of achieving scalable and economically viable solar hydrogen production. To obtain high solar energy conversion efficiency, the quantum efficiency of the photocatalytic reaction must be increased over a wide range of wavelengths and semiconductors with narrow bandgaps need to be designed. However, the quantum efficiency associated with overall Water Splitting using existing photocatalysts is typically lower than ten per cent1,2. Thus, whether a particulate photocatalyst can enable a quantum efficiency of 100 per cent for the greatly endergonic Water-Splitting reaction remains an open question. Here we demonstrate overall Water Splitting at an external quantum efficiency of up to 96 per cent at wavelengths between 350 and 360 nanometres, which is equivalent to an internal quantum efficiency of almost unity, using a modified aluminium-doped strontium titanate (SrTiO3:Al) photocatalyst3,4. By selectively photodepositing the cocatalysts Rh/Cr2O3 (ref. 5) and CoOOH (refs. 3,6) for the hydrogen and oxygen evolution reactions, respectively, on different crystal facets of the semiconductor particles using anisotropic charge transport, the hydrogen and oxygen evolution reactions could be promoted separately. This enabled multiple consecutive forward charge transfers without backward charge transfer, reaching the upper limit of quantum efficiency for overall Water Splitting. Our work demonstrates the feasibility of overall Water Splitting free from charge recombination losses and introduces an ideal cocatalyst/photocatalyst structure for efficient Water Splitting. Water Splitting with an internal quantum efficiency of almost unity is achieved using a modified semiconductor photocatalyst that selectively promotes the hydrogen and oxygen evolution reactions on separate crystal facets.
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Visible-Light-Driven Photocatalytic Water Splitting: Recent Progress and Challenges
Trends in Chemistry, 2020Co-Authors: Lihua Lin, Takashi Hisatomi, Tsuyoshi Takata, Shanshan Chen, Kazunari DomenAbstract:Sunlight-driven photocatalytic Water Splitting is one of the most promising approaches to generating renewable hydrogen as an energy source. In recent years, significant progress has been made in the development of photocatalytic Water-Splitting systems. Among these, the one- and two-step-excitation overall Water-Splitting processes are most widely investigated. Realization of visible-light-driven overall Water Splitting is one of the most important goals at present because of the need to obtain systems exhibiting high solar-to-hydrogen energy conversion efficiency for practical applications. The present review focuses on recent progress in the field of photocatalytic Water Splitting, especially in the research and design of visible-light-driven overall Water-Splitting systems, and outlines potential strategies to overcome the difficulties related to practical applications.
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particulate photocatalysts for overall Water Splitting
Nature Reviews Materials, 2017Co-Authors: Shanshan Chen, Tsuyoshi Takata, Kazunari DomenAbstract:Overall Water Splitting using powdered photocatalysts is a promising approach to large-scale solar hydrogen production. This Review details recent developments in particulate photocatalysts for overall Water Splitting based on one- and two-step photoexcitation systems.
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Particulate photocatalysts for overall Water Splitting
Nature Reviews Materials, 2017Co-Authors: Shanshan Chen, Tsuyoshi Takata, Kazunari DomenAbstract:Overall Water Splitting using powdered photocatalysts is a promising approach to large-scale solar hydrogen production. This Review details recent developments in particulate photocatalysts for overall Water Splitting based on one- and two-step photoexcitation systems. The conversion of solar energy to chemical energy is a promising way of generating renewable energy. Hydrogen production by means of Water Splitting over semiconductor photocatalysts is a simple, cost-effective approach to large-scale solar hydrogen synthesis. Since the discovery of the Honda–Fujishima effect, considerable progress has been made in this field, and numerous photocatalytic materials and Water-Splitting systems have been developed. In this Review, we summarize existing Water-Splitting systems based on particulate photocatalysts, focusing on the main components: light-harvesting semiconductors and co-catalysts. The essential design principles of the materials employed for overall Water-Splitting systems based on one-step and two-step photoexcitation are also discussed, concentrating on three elementary processes: photoabsorption, charge transfer and surface catalytic reactions. Finally, we outline challenges and potential advances associated with solar Water Splitting by particulate photocatalysts for future commercial applications.
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Solar hydrogen production on some Water Splitting photocatalysts
Solar Hydrogen and Nanotechnology XI, 2016Co-Authors: Tsuyoshi Takata, Takashi Hisatomi, Kazunari DomenAbstract:Photocatalytic overall Water Splitting into H2 and O2 is expected to be a promising method for the efficient utilization of solar energy. The design of optimal photocatalyst structures is a key to efficient overall Water Splitting, and the development of photocatalysts which can efficiently convert large portion of visible light spectrum has been required. Recently, a series of complex perovskite type transition metal oxynitrides, LaMgxT 1-xO1+3xN2-3x, was developed as photocatalysts for direct Water Splitting operable at wide wavelength of visible light. In addition two-step excitation Water Splitting via a novel photocatalytic device termed as photocatalyst sheet was developed. This consists of two types of semiconductors (hydrogen evolution photocatalyst and oxygen evolution photocatalyst) particles embedded in a conductive layer, and showed high efficiency for overall Water Splitting. These recent advances in photocatalytic Water Splitting were introduced.
Can Li - One of the best experts on this subject based on the ideXlab platform.
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Photocatalytic Water Splitting on Semiconductor-Based Photocatalysts
Advances in Catalysis, 2017Co-Authors: Rengui Li, Can LiAbstract:Photocatalytic hydrogen production via solar Water Splitting is one of the most promising solutions for sustainable energy and environmental remedy issues. In the past few decades, photocatalytic Water Splitting has attracted increasing attention, and extensive efforts have been made to construct efficient heterogeneous Water-Splitting systems. In this chapter, we review the fundamental scientific advances in photocatalytic Water Splitting using semiconductor-based photocatalyst, especially in light-absorbing materials, photogenerated charge separation, dual-cocatalyst, and surface catalytic reactions. The chapter focuses on the advances achieved in particulate photocatalyst systems, Z-scheme photocatalyst systems, and hybrid natural–artificial photosynthesis systems. Additionally, technical and economic evaluation of hydrogen production via solar Water Splitting for potential applications is also briefly discussed. Finally, we present concluding remarks and future directions of photocatalytic Water Splitting for solar energy conversion.
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Semiconductor-Based Photocatalytic Water Splitting
Lecture Notes in Energy, 2016Co-Authors: Fuxiang Zhang, Can LiAbstract:Solar to chemical energy conversion from Water by powdered photocatalyst is one of the most promising approaches. In this chapter, we will introduce some bases of photocatalytic Water Splitting, and key issues and challenges for solar Water Splitting. At the same time, the basic mechanism, processes, reaction systems as well as strategies for light absorption, charge separation and catalytic conversion will be summarized and discussed.
