The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Elijah Thimsen - One of the best experts on this subject based on the ideXlab platform.
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highly active Oxide photocathode for photoelectrochemical water reduction
Nature Materials, 2011Co-Authors: Adriana Paracchino, Vincent Laporte, Elijah Thimsen, Kevin Sivula, Michael GratzelAbstract:Production of chemical fuels by solar energy is an attractive and sustainable solution to our energy problems. A highly active photocathode, consisting of electrodeposited Cuprous Oxide with platinum nanoparticles is now activated for hydrogen evolution resulting from photelectrochemical water reduction.
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Highly active Oxide photocathode for photoelectrochemical water reduction
Nature Materials, 2011Co-Authors: Adriana Paracchino, Vincent Laporte, Kevin Sivula, Elijah ThimsenAbstract:A clean and efficient way to overcome the limited supply of fossil fuels and the greenhouse effect is the production of hydrogen fuel from sunlight and water through the semiconductor/water junction of a photoelectrochemical cell, where energy collection and water electrolysis are combined into a single semiconductor electrode. We present a highly active photocathode for solar H(2) production, consisting of electrodeposited Cuprous Oxide, which was protected against photocathodic decomposition in water by nanolayers of Al-doped zinc Oxide and titanium Oxide and activated for hydrogen evolution with electrodeposited Pt nanoparticles. The roles of the different surface protection components were investigated, and in the best case electrodes showed photocurrents of up to -7.6 mA cm(-2) at a potential of 0 V versus the reversible hydrogen electrode at mild pH. The electrodes remained active after 1 h of testing, Cuprous Oxide was found to be stable during the water reduction reaction and the Faradaic efficiency was estimated to be close to 100%.
Michael Gratzel - One of the best experts on this subject based on the ideXlab platform.
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photoelectrochemical deposition of cop on Cuprous Oxide photocathodes for solar hydrogen production
Electrochimica Acta, 2017Co-Authors: Lucasalexandre Stern, Matthew T Mayer, Laurent Liardet, Carlos G Moralesguio, Michael GratzelAbstract:Abstract Photoelectrochemical (PEC) water splitting is an attractive and sustainable energy conversion method. In this work, cobalt phosphide (CoP) is photoelectrochemically deposited on a p -type Cuprous Oxide ( p -Cu 2 O) photocathode for solar hydrogen production. Under visible light irradiation, the PEC assembly is active for hydrogen evolution, generating a current density of up to −5.3 mA cm −2 and −4.2 mA cm −2 in acidic and basic conditions at 0 V vs . the reversible hydrogen electrode (RHE).
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a copper nickel mixed Oxide hole selective layer for au free transparent Cuprous Oxide photocathodes
Energy and Environmental Science, 2017Co-Authors: Min Kyu Son, Marcel Schreier, Jingshan Luo, Matthew T Mayer, Ludmilla Steier, Michael GratzelAbstract:State-of-the-art Cuprous Oxide (Cu2O) photocathodes for photoelectrochemical (PEC) water splitting have a long tradition of using gold (Au)-coated F-doped SnO2 (FTO) substrates for the improvement of Cu2O electrodeposition and overall PEC performance. Au is one of the best contact materials for Cu2O photocathodes due to its large work function enabling proper alignment with the valence band level of Cu2O. Due to its relatively large band gap (2.0 eV), Cu2O is preferentially used as the top-cell absorber in tandem with a photoanode or a photovoltaic (PV) cell for overall solar-driven water splitting. However, the Au contact poses a major issue due to its poor transparency. Moreover, Au is a precious metal, which increases the cost and can hinder the scalability of PEC devices. In this work, we propose an effective replacement of the Au layer with a transparent and cost-efficient copper-nickel mixed Oxide (CuO/NiO) thin film, which is prepared by a facile sequential sputtering deposition combined with an annealing process in air. We successfully demonstrate that a thin layer of the CuO/NiO film shows better transparency as well as well-aligned energy levels for efficient hole collection leading to an improved PEC performance compared to the performance of a Au-contact based equivalent device in a pH 5 electrolyte biased at 0 V versus the reversible hydrogen electrode. This new transparent and efficient CuO/NiO layer paves the way for the development of efficient, yet inexpensive PEC–PV or photocathode–photoanode stacked tandem devices for a hydrogen fuel based economy.
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tin Oxide as stable protective layer for composite Cuprous Oxide water splitting photocathodes
Nano Energy, 2016Co-Authors: Joao Lucio De Azevedo, C. T. Sousa, Mark. Stefik, Michael Gratzel, David S Tilley, Marcel Schreier, Adelio Mendes, J P Araujo, Matthew T MayerAbstract:Abstract For a sustainable future, efficient solar energy harvesting and storage is required. Solar hydrogen production from photoelectrochemical water splitting is a promising technology and, in particular, Cuprous Oxide photocathodes are interesting photoelectrodes due to their high efficiency and low cost. However, chemical instability inhibits practical application of such devices. This work reports a novel strategy for protecting Cuprous Oxide from photocorrosion, wherein a thin SnO2 overlayer enables increased stability over previous reports utilizing TiO2 protective layers. Performance and stability are influenced by the film thickness, post-deposition steam treatment, and the nature of the heterojunction interface. Stability over 57 h of sustained photoelectrochemical water reduction, maintaining 90% of initial photocurrent, is achieved.
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transparent Cuprous Oxide photocathode enabling a stacked tandem cell for unbiased water splitting
Advanced Energy Materials, 2015Co-Authors: Paula Dias, Michael Gratzel, David S Tilley, Marcel Schreier, Jingshan Luo, Joao Lucio De Azevedo, Luisa Andrade, Adelio Mendes, Matthew T MayerAbstract:Photoelectrochemical water splitting represents an attractive method of capturing and storing the immense energy of sunlight in the form of hydrogen, a clean chemical fuel. Given the large energetic demand of water electrolysis, and the defined spectrum of photons available from incident sunlight, a two absorber tandem device is required to achieve high efficiencies. The two absorbers should be of different and complementary bandgaps, connected in series to achieve the necessary voltage, and arranged in an optical stack configuration to maximize the utilization of sunlight. This latter requirement demands a top device that is responsive to high-energy photons but also transparent to lower-energy photons, which pass through to illuminate the bottom absorber. Here, Cuprous Oxide (Cu2O) is employed as a top absorber component, and the factors influencing the balance between transparency and efficiency toward operation in a tandem configuration are studied. Photocathodes based on Cu2O electrodeposited onto conducting glass substrates treated with thin, discontinuous layers of gold achieve reasonable sub-bandgap transmittance while retaining performances comparable to their opaque counterparts. This new high-performance transparent photocathode is demonstrated in tandem with a hybrid perovskite photovoltaic cell, resulting in a full device capable of standalone sunlight-driven water splitting.
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highly active Oxide photocathode for photoelectrochemical water reduction
Nature Materials, 2011Co-Authors: Adriana Paracchino, Vincent Laporte, Elijah Thimsen, Kevin Sivula, Michael GratzelAbstract:Production of chemical fuels by solar energy is an attractive and sustainable solution to our energy problems. A highly active photocathode, consisting of electrodeposited Cuprous Oxide with platinum nanoparticles is now activated for hydrogen evolution resulting from photelectrochemical water reduction.
Matthew T Mayer - One of the best experts on this subject based on the ideXlab platform.
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photoelectrochemical deposition of cop on Cuprous Oxide photocathodes for solar hydrogen production
Electrochimica Acta, 2017Co-Authors: Lucasalexandre Stern, Matthew T Mayer, Laurent Liardet, Carlos G Moralesguio, Michael GratzelAbstract:Abstract Photoelectrochemical (PEC) water splitting is an attractive and sustainable energy conversion method. In this work, cobalt phosphide (CoP) is photoelectrochemically deposited on a p -type Cuprous Oxide ( p -Cu 2 O) photocathode for solar hydrogen production. Under visible light irradiation, the PEC assembly is active for hydrogen evolution, generating a current density of up to −5.3 mA cm −2 and −4.2 mA cm −2 in acidic and basic conditions at 0 V vs . the reversible hydrogen electrode (RHE).
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a copper nickel mixed Oxide hole selective layer for au free transparent Cuprous Oxide photocathodes
Energy and Environmental Science, 2017Co-Authors: Min Kyu Son, Marcel Schreier, Jingshan Luo, Matthew T Mayer, Ludmilla Steier, Michael GratzelAbstract:State-of-the-art Cuprous Oxide (Cu2O) photocathodes for photoelectrochemical (PEC) water splitting have a long tradition of using gold (Au)-coated F-doped SnO2 (FTO) substrates for the improvement of Cu2O electrodeposition and overall PEC performance. Au is one of the best contact materials for Cu2O photocathodes due to its large work function enabling proper alignment with the valence band level of Cu2O. Due to its relatively large band gap (2.0 eV), Cu2O is preferentially used as the top-cell absorber in tandem with a photoanode or a photovoltaic (PV) cell for overall solar-driven water splitting. However, the Au contact poses a major issue due to its poor transparency. Moreover, Au is a precious metal, which increases the cost and can hinder the scalability of PEC devices. In this work, we propose an effective replacement of the Au layer with a transparent and cost-efficient copper-nickel mixed Oxide (CuO/NiO) thin film, which is prepared by a facile sequential sputtering deposition combined with an annealing process in air. We successfully demonstrate that a thin layer of the CuO/NiO film shows better transparency as well as well-aligned energy levels for efficient hole collection leading to an improved PEC performance compared to the performance of a Au-contact based equivalent device in a pH 5 electrolyte biased at 0 V versus the reversible hydrogen electrode. This new transparent and efficient CuO/NiO layer paves the way for the development of efficient, yet inexpensive PEC–PV or photocathode–photoanode stacked tandem devices for a hydrogen fuel based economy.
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tin Oxide as stable protective layer for composite Cuprous Oxide water splitting photocathodes
Nano Energy, 2016Co-Authors: Joao Lucio De Azevedo, C. T. Sousa, Mark. Stefik, Michael Gratzel, David S Tilley, Marcel Schreier, Adelio Mendes, J P Araujo, Matthew T MayerAbstract:Abstract For a sustainable future, efficient solar energy harvesting and storage is required. Solar hydrogen production from photoelectrochemical water splitting is a promising technology and, in particular, Cuprous Oxide photocathodes are interesting photoelectrodes due to their high efficiency and low cost. However, chemical instability inhibits practical application of such devices. This work reports a novel strategy for protecting Cuprous Oxide from photocorrosion, wherein a thin SnO2 overlayer enables increased stability over previous reports utilizing TiO2 protective layers. Performance and stability are influenced by the film thickness, post-deposition steam treatment, and the nature of the heterojunction interface. Stability over 57 h of sustained photoelectrochemical water reduction, maintaining 90% of initial photocurrent, is achieved.
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transparent Cuprous Oxide photocathode enabling a stacked tandem cell for unbiased water splitting
Advanced Energy Materials, 2015Co-Authors: Paula Dias, Michael Gratzel, David S Tilley, Marcel Schreier, Jingshan Luo, Joao Lucio De Azevedo, Luisa Andrade, Adelio Mendes, Matthew T MayerAbstract:Photoelectrochemical water splitting represents an attractive method of capturing and storing the immense energy of sunlight in the form of hydrogen, a clean chemical fuel. Given the large energetic demand of water electrolysis, and the defined spectrum of photons available from incident sunlight, a two absorber tandem device is required to achieve high efficiencies. The two absorbers should be of different and complementary bandgaps, connected in series to achieve the necessary voltage, and arranged in an optical stack configuration to maximize the utilization of sunlight. This latter requirement demands a top device that is responsive to high-energy photons but also transparent to lower-energy photons, which pass through to illuminate the bottom absorber. Here, Cuprous Oxide (Cu2O) is employed as a top absorber component, and the factors influencing the balance between transparency and efficiency toward operation in a tandem configuration are studied. Photocathodes based on Cu2O electrodeposited onto conducting glass substrates treated with thin, discontinuous layers of gold achieve reasonable sub-bandgap transmittance while retaining performances comparable to their opaque counterparts. This new high-performance transparent photocathode is demonstrated in tandem with a hybrid perovskite photovoltaic cell, resulting in a full device capable of standalone sunlight-driven water splitting.
Marcel Schreier - One of the best experts on this subject based on the ideXlab platform.
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a copper nickel mixed Oxide hole selective layer for au free transparent Cuprous Oxide photocathodes
Energy and Environmental Science, 2017Co-Authors: Min Kyu Son, Marcel Schreier, Jingshan Luo, Matthew T Mayer, Ludmilla Steier, Michael GratzelAbstract:State-of-the-art Cuprous Oxide (Cu2O) photocathodes for photoelectrochemical (PEC) water splitting have a long tradition of using gold (Au)-coated F-doped SnO2 (FTO) substrates for the improvement of Cu2O electrodeposition and overall PEC performance. Au is one of the best contact materials for Cu2O photocathodes due to its large work function enabling proper alignment with the valence band level of Cu2O. Due to its relatively large band gap (2.0 eV), Cu2O is preferentially used as the top-cell absorber in tandem with a photoanode or a photovoltaic (PV) cell for overall solar-driven water splitting. However, the Au contact poses a major issue due to its poor transparency. Moreover, Au is a precious metal, which increases the cost and can hinder the scalability of PEC devices. In this work, we propose an effective replacement of the Au layer with a transparent and cost-efficient copper-nickel mixed Oxide (CuO/NiO) thin film, which is prepared by a facile sequential sputtering deposition combined with an annealing process in air. We successfully demonstrate that a thin layer of the CuO/NiO film shows better transparency as well as well-aligned energy levels for efficient hole collection leading to an improved PEC performance compared to the performance of a Au-contact based equivalent device in a pH 5 electrolyte biased at 0 V versus the reversible hydrogen electrode. This new transparent and efficient CuO/NiO layer paves the way for the development of efficient, yet inexpensive PEC–PV or photocathode–photoanode stacked tandem devices for a hydrogen fuel based economy.
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tin Oxide as stable protective layer for composite Cuprous Oxide water splitting photocathodes
Nano Energy, 2016Co-Authors: Joao Lucio De Azevedo, C. T. Sousa, Mark. Stefik, Michael Gratzel, David S Tilley, Marcel Schreier, Adelio Mendes, J P Araujo, Matthew T MayerAbstract:Abstract For a sustainable future, efficient solar energy harvesting and storage is required. Solar hydrogen production from photoelectrochemical water splitting is a promising technology and, in particular, Cuprous Oxide photocathodes are interesting photoelectrodes due to their high efficiency and low cost. However, chemical instability inhibits practical application of such devices. This work reports a novel strategy for protecting Cuprous Oxide from photocorrosion, wherein a thin SnO2 overlayer enables increased stability over previous reports utilizing TiO2 protective layers. Performance and stability are influenced by the film thickness, post-deposition steam treatment, and the nature of the heterojunction interface. Stability over 57 h of sustained photoelectrochemical water reduction, maintaining 90% of initial photocurrent, is achieved.
-
transparent Cuprous Oxide photocathode enabling a stacked tandem cell for unbiased water splitting
Advanced Energy Materials, 2015Co-Authors: Paula Dias, Michael Gratzel, David S Tilley, Marcel Schreier, Jingshan Luo, Joao Lucio De Azevedo, Luisa Andrade, Adelio Mendes, Matthew T MayerAbstract:Photoelectrochemical water splitting represents an attractive method of capturing and storing the immense energy of sunlight in the form of hydrogen, a clean chemical fuel. Given the large energetic demand of water electrolysis, and the defined spectrum of photons available from incident sunlight, a two absorber tandem device is required to achieve high efficiencies. The two absorbers should be of different and complementary bandgaps, connected in series to achieve the necessary voltage, and arranged in an optical stack configuration to maximize the utilization of sunlight. This latter requirement demands a top device that is responsive to high-energy photons but also transparent to lower-energy photons, which pass through to illuminate the bottom absorber. Here, Cuprous Oxide (Cu2O) is employed as a top absorber component, and the factors influencing the balance between transparency and efficiency toward operation in a tandem configuration are studied. Photocathodes based on Cu2O electrodeposited onto conducting glass substrates treated with thin, discontinuous layers of gold achieve reasonable sub-bandgap transmittance while retaining performances comparable to their opaque counterparts. This new high-performance transparent photocathode is demonstrated in tandem with a hybrid perovskite photovoltaic cell, resulting in a full device capable of standalone sunlight-driven water splitting.
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ruthenium Oxide hydrogen evolution catalysis on composite Cuprous Oxide water splitting photocathodes
Advanced Functional Materials, 2014Co-Authors: David S Tilley, Mark. Stefik, Marcel Schreier, Joao Lucio De Azevedo, Michael GraetzelAbstract:Photocathodes based on Cuprous Oxide (Cu2O) are promising materials for large scale and widespread solar fuel generation due to the abundance of copper, suitable bandgap, and favorable band alignments for reducing water and carbon diOxide. A protective overlayer is required to stabilize the Cu2O in aqueous media under illumination, and the interface between this overlayer and the catalyst nanoparticles was previously identified as a key source of instability. Here, the properties of the protective titanium diOxide overlayer ofcomposite Cuprous Oxide photocathodes are further investigated, as well as an Oxide-based hydrogen evolution catalyst, ruthenium Oxide (RuO2). The RuO2-catalyzed photoelectrodes exhibit much improved stability versus platinum nanoparticles, with 94% stability after 8 h of light-chopping chronoamperometry. Faradaic efficiencies of approximate to 100% are obtained as determined by measurement of the evolved hydrogen gas. The sustained photocurrents of close to 5 mA cm(-2) obtained with this electrode during the chronoamperometry measurement (at 0 V vs. the reversible hydrogen electrode, pH 5, and simulated 1 sun illumination) would correspond to greater than 6% solar-to-hydrogen conversion efficiency in a tandem photoelectrochemical cell, where the bias is provided by a photovoltaic device such as a dye-sensitized solar cell.
Adriana Paracchino - One of the best experts on this subject based on the ideXlab platform.
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highly active Oxide photocathode for photoelectrochemical water reduction
Nature Materials, 2011Co-Authors: Adriana Paracchino, Vincent Laporte, Elijah Thimsen, Kevin Sivula, Michael GratzelAbstract:Production of chemical fuels by solar energy is an attractive and sustainable solution to our energy problems. A highly active photocathode, consisting of electrodeposited Cuprous Oxide with platinum nanoparticles is now activated for hydrogen evolution resulting from photelectrochemical water reduction.
-
Highly active Oxide photocathode for photoelectrochemical water reduction
Nature Materials, 2011Co-Authors: Adriana Paracchino, Vincent Laporte, Kevin Sivula, Elijah ThimsenAbstract:A clean and efficient way to overcome the limited supply of fossil fuels and the greenhouse effect is the production of hydrogen fuel from sunlight and water through the semiconductor/water junction of a photoelectrochemical cell, where energy collection and water electrolysis are combined into a single semiconductor electrode. We present a highly active photocathode for solar H(2) production, consisting of electrodeposited Cuprous Oxide, which was protected against photocathodic decomposition in water by nanolayers of Al-doped zinc Oxide and titanium Oxide and activated for hydrogen evolution with electrodeposited Pt nanoparticles. The roles of the different surface protection components were investigated, and in the best case electrodes showed photocurrents of up to -7.6 mA cm(-2) at a potential of 0 V versus the reversible hydrogen electrode at mild pH. The electrodes remained active after 1 h of testing, Cuprous Oxide was found to be stable during the water reduction reaction and the Faradaic efficiency was estimated to be close to 100%.
