Solar energy driven photoelectrochemical(PEC) water splitting is a clean and powerful approach for renewable hydrogen production. The design and construction of metal oxide based nanoarray photoanodes is one of the pr...Solar energy driven photoelectrochemical(PEC) water splitting is a clean and powerful approach for renewable hydrogen production. The design and construction of metal oxide based nanoarray photoanodes is one of the promising strategies to make the continuous breakthroughs in solar to hydrogen conversion efficiency of PEC cells owing to their owned several advantages including enhanced reactive surface at the electrode/electrolyte interface, improved light absorption capability, increased charge separation efficiency and direct electron transport pathways. In this Review, we first introduce the structure,work principle and their relevant efficiency calculations of a PEC cell. We then give a summary of the state-of the-art research in the preparation strategies and growth mechanism for the metal oxide based nanoarrays, and some details about the performances of metal oxide based nanoarray photoanodes for PEC water splitting. Finally, we discuss key aspects which should be addressed in continued work on realizing high-efficiency metal oxide based nanoarray photoanodes for PEC solar water splitting systems.展开更多
Surface treatment is an effective method to improve the photoelectrochemical(PEC) performance of photoelectrodes. Herein, we introduced a novel strategy of surface sulfurization to modify hematite(a-Fe2 O3)nanorods gr...Surface treatment is an effective method to improve the photoelectrochemical(PEC) performance of photoelectrodes. Herein, we introduced a novel strategy of surface sulfurization to modify hematite(a-Fe2 O3)nanorods grown in an aqueous solution, which triggered encouraging improvement in PEC performances.In comparison to the solution-grown pristine a-Fe2 O3 nanorod photoanode that is PEC inefficient and always needs high temperature(>600 °C) activation, the surface sulfurized a-Fe2 O3 nanorods show photocurrent density increased by orders of magnitude, reaching 0.46 mA cmà2 at 1.23 V vs. RHE(reversible hydrogen electrode) under simulated solar illumination. This improvement in PEC performances should be attributed to the synergy of the increased carrier density, the reduced surface charge carrier recombination and the accelerated water oxidation kinetics at the a-Fe2 O3/electrolyte interface, as induced by the incorporation of S ions and the formation of multi-state S species(Fe-Sx-Oy) at the surface of a-Fe2 O3 nanorods. This study paves a new and facile approach to activate a-Fe2 O3 and even other metal oxides as photoelectrodes for improved PEC water splitting performances, by engineering the surface structure to relieve the bottlenecks of charge transfer dynamics and redox reaction kinetics at the electrode/electrolyte interface.展开更多
The effect of chromium doping on the photo- voltaic efficiency of dye-sensitized solar cells （DSSCs） with anodized TiO2 nanotubes followed by an annealing process was investigated. Cr-doped TiO2 nanotubes （CrTNs） ...The effect of chromium doping on the photo- voltaic efficiency of dye-sensitized solar cells （DSSCs） with anodized TiO2 nanotubes followed by an annealing process was investigated. Cr-doped TiO2 nanotubes （CrTNs） with different amounts of chromium were obtained by anodizing of titanium foils in a single-step process using potassium chro- mate as the chromium source. Film features were investigated by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy-dispersive X-ray spectroscopy （EDX）, and ultraviolet-visible （UV-Vis） spectroscopy. It is clearly seen that highly ordered TiO2 nanotubes are formed in an anodizing solution free of potassium chromate, and with a gradual increase in the potassium chromate concentration, these nanotube structures change to nanoporous and compact films without porosity. The photovoltaic efficiencies of fabricated DSSCs were characterized by a solar cell measurement sys- tem via the photocurrent-voltage （l-V） curves. It is found that the photovoltaic efficiency of DSSCs with CrTNsl sample is improved by more than three times compared to that of DSSCs with undoped TNs. The energy conversion efficiency increases from 1.05 % to 3.89 % by doping of chromium.展开更多
通过水热法成功制备了ZnO:Mg@CuWO_(4)复合材料,首先使用XRD、SEM等测试方法对各个样品进行表征,而后进行光电催化测试以确定各样品的光电催化活性。实验表明,ZnO:Mg@CuWO_(4)复合材料比纯相CuWO_(4)具有更高的光电催化活性,且与纯相ZnO...通过水热法成功制备了ZnO:Mg@CuWO_(4)复合材料,首先使用XRD、SEM等测试方法对各个样品进行表征,而后进行光电催化测试以确定各样品的光电催化活性。实验表明,ZnO:Mg@CuWO_(4)复合材料比纯相CuWO_(4)具有更高的光电催化活性,且与纯相ZnO:Mg相比提高了稳定性。ZnO:Mg@CuWO_(4)复合材料成功提升了光阳极的光电流密度(约0.28 mA/cm2@1.23 V vs.RHE),是纯相CuWO_(4)(约0.16 mA/cm2@1.23 V vs.RHE)光阳极的1.8倍。ZnO:Mg@CuWO_(4)复合材料提高了表面电荷注入与分离效率,促进了界面电荷的转移,减少了光生载流子复合,从而提高了CuWO_(4)的光电催化效率。展开更多
4H silicon carbide(4H-SiC)has gained a great success in high-power electronics,owing to its advantages of wide bandgap,high breakdown electric field strength,high carrier mobility,and high thermal conductivity.Conside...4H silicon carbide(4H-SiC)has gained a great success in high-power electronics,owing to its advantages of wide bandgap,high breakdown electric field strength,high carrier mobility,and high thermal conductivity.Considering the high carrier mobility and high stability of 4H-SiC,4H-SiC has great potential in the field of photoelectrochemical(PEC)water splitting.In this work,we demonstrate the irradiation-resistant PEC water splitting based on nanoporous 4H-SiC arrays.A new two-step anodizing approach is adopted to prepare 4H-SiC nanoporous arrays with different porosity,that is,a constant low-voltage etching followed by a pulsed high-voltage etching.The constant-voltage etching and pulsed-voltage etching are adopted to control the diameter of the nanopores and the depth of the nanoporous arrays,respectively.It is found that the nanoporous arrays with medium porosity has the highest PEC current,because of the enhanced light absorption and the optimized transportation of charge carriers along the walls of the nanoporous arrays.The performance of the PEC water splitting of the nanoporous arrays is stable after the electron irradiation with the dose of 800 and 1600 k Gy,which indicates that 4H-SiC nanoporous arrays has great potential in the PEC water splitting under harsh environments.展开更多
Photoelectrochemical(PEC)water splitting can convert renewable solar energy into clean hydrogen fuel.Photoelectrodes are the core components of water-splitting cells.In the past 40 years,a series of binary and ternary...Photoelectrochemical(PEC)water splitting can convert renewable solar energy into clean hydrogen fuel.Photoelectrodes are the core components of water-splitting cells.In the past 40 years,a series of binary and ternary transition metal oxides have been investigated as photo-electrode materials for solar water splitting,and numerous studies have been carried out to modify their water-split-ting performances.Although satisfactory transition metal oxide photoelectrode materials have not been found,it is necessary to summarize the recent advancements in tran-sition metal oxide photoelectrode materials to guide future research.In this review,the background and principle of PEC water splitting are introduced.The semiconductor properties and modification progress of typical binary and ternary metal oxide photoanodes and photocathodes for solar water splitting are summarized.Based on the newly developed strategies in recent years,a brief outlook is presented for efficient PEC water splitting using transition metal oxide photoelectrodes.展开更多
In this work, a three-layer TiO2 composite film consisting of flower-like TiO2 （Flo-TiO2） as overlayer, TiOa nanotube arrays as interlayer and TiO2 nanoparticle （P25） as underlayer was fabricated as the photoelect...In this work, a three-layer TiO2 composite film consisting of flower-like TiO2 （Flo-TiO2） as overlayer, TiOa nanotube arrays as interlayer and TiO2 nanoparticle （P25） as underlayer was fabricated as the photoelectrode of dyesensitized solar cells （DSSCs）. Due to the introduction of Flo-TiO2, the three-layer composite film has strong lightscattering ability. Then, we have investigated and compared the photoelectric conversion properties of DSSCs based on three-layer structure （P25/TNT arrays/Flo-TiO2） photoelectrode and double-layer film （P25/TNT arrays） photoelectrode. It is found that DSSCs based on three-layer structure exhibit a high power conversion efficiency of 6.48% compared with the DSSCs composed of double-layer film （5.11%）.展开更多
近年来,基于BiVO_(4)光阳极的光电催化分解水技术引起人们的关注.我们通过水热-氨化法制备出Ni_(3)N纳米颗粒,首次将其作为助催化剂修饰到BiVO_(4)光阳极上光电催化分解水.实验表明, Ni_(3)N纳米颗粒成功负载到BiVO_(4)光阳极表面并可...近年来,基于BiVO_(4)光阳极的光电催化分解水技术引起人们的关注.我们通过水热-氨化法制备出Ni_(3)N纳米颗粒,首次将其作为助催化剂修饰到BiVO_(4)光阳极上光电催化分解水.实验表明, Ni_(3)N纳米颗粒成功负载到BiVO_(4)光阳极表面并可有效抑制表面电荷复合以及提高光电催化分解水性能.在1.23 V v. RHE处光电流密度可达3.23mA/cm^(2).此外, Ni_(3)N/BiVO_(4)光阳极的最大值ABPE值达0.88%,并呈现出良好的稳定性.展开更多
TiO2 photoanodes have aroused intensive research interest in photoelectrochemical （PEC） water splitting. However, they still suffer from poor electron-hole separation and sluggish oxygen evolution dynamics, leading ...TiO2 photoanodes have aroused intensive research interest in photoelectrochemical （PEC） water splitting. However, they still suffer from poor electron-hole separation and sluggish oxygen evolution dynamics, leading to the low photoconversion efficiency and limiting commercial application. Here, we designed and fabricated novel ternary non-noble metal carbonate hydroxide （ZNC-CH） nanosheet cocatalysts and integrated them with TiO2 nanorod arrays as highly efficient photoanodes of PEC cells. Compared with the pristine TiO2, the photocurrent of photoanode with the optimal amount of ZNC-CH represents 3.2 times enhancement, and the onset potential is shifted toward the negative potential direction of 62 mV, The remarkable enhancement is attributed to the suppressed carrier recombination and enhanced charge transfer efficiency at the interface of TiO2, ZNC-CH and electrolyte, which is closely related to the zinc elements modulated intrinsic activity of catalysts. Our results demonstrate that the introduction of multimetallic ZNC-CH cocatalysts onto photoanodes is a promising strategy to improve the PEC efficiency.展开更多
Z-scheme photocatalytic system has been regarded as a popular field of research in photoelectrochemical(PEC)water splitting.Among the many obstacles facing a Z-scheme photocatalytic system,the analysis methods of inte...Z-scheme photocatalytic system has been regarded as a popular field of research in photoelectrochemical(PEC)water splitting.Among the many obstacles facing a Z-scheme photocatalytic system,the analysis methods of interfacial Z-scheme charge transfer still remain a significant challenge.Hence,in this study,CdS/Ti-Fe_(2)O_(3)heterojunction photoanodes are elaborately designed to explore the charge-transfer behavior in PEC water splitting.In this study,photophysical measurements,including the Kelvin probe measurement,surface photovoltage spectroscopy(SPV),and transient photovoltage spectroscopy(TPV),are used to monitor the migration behavior of photogenerated charges at the interface electric field of CdS/Ti-Fe_(2)O_(3)Z-scheme heterojunction photoanodes.The Kelvin probe and SPV measurements demonstrate that CdS/Ti-Fe_(2)O_(3)interfacial driving force favors the rapid transfer of photoexcited electrons to CdS.The double-beam strategy based on TPV indicates that more electrons of Ti-Fe_(2)O_(3)are combined with the holes of CdS owing to the intensive interface electric field.The results of these measurements successfully prove the Z-scheme migration mechanism of CdS/Ti-Fe_(2)O_(3)photoanodes.Benefiting from the desirable charge transfer at the interface electric field,CdS/Ti-Fe_(2)O_(3)photoanodes exhibit superior photocatalytic oxygen evolution reaction performance compared with that of pure Ti-Fe_(2)O_(3).The photocurrent density of the 25CdS/Ti-Fe_(2)O_(3)photoanode reaches 1.94 mA/cm^(2) at 1.23 V versus reversible hydrogen electrode without excess cocatalyst,and it is two times higher than that of pure Ti-Fe_(2)O_(3)photoanode.Therefore,an outstanding strategy is provided in this study to prove the Z-scheme charge-transfer mechanism of photocatalytic systems in PEC water splitting.展开更多
通过滴涂法成功制备了Bi_(2)WO_(6)/Fe_(2)O_(3)复合材料,利用XRD、SEM等方法进行表征和一系列光电催化测试。结果表明,Bi_(2)WO_(6)/Fe_(2)O_(3)复合材料比纯相Fe_(2)O_(3)具有更好的催化活性,且滴涂10μL Bi_(2)WO_(6)前驱体溶液的Bi_...通过滴涂法成功制备了Bi_(2)WO_(6)/Fe_(2)O_(3)复合材料,利用XRD、SEM等方法进行表征和一系列光电催化测试。结果表明,Bi_(2)WO_(6)/Fe_(2)O_(3)复合材料比纯相Fe_(2)O_(3)具有更好的催化活性,且滴涂10μL Bi_(2)WO_(6)前驱体溶液的Bi_(2)WO_(6)/Fe_(2)O_(3)光阳极具有最高的光电流密度(0.15 mA·cm^(-2)@1.23 V vs.RHE),是纯相Fe_(2)O_(3)(约4.4μA·cm^(-2)@1.23 V vs.RHE)光电阳极的34倍。复合材料的形成增加了吸收光谱范围,提高了对可见光的利用率,促进了界面电荷转移,抑制了光生载流子复合,从而提高了Fe_(2)O_(3)的光电催化活性。展开更多
基金supported by the National Key Research and Development Program of China (2018YFA0209600)Shenzhen Peacock Plan (KQTD2016053015544057)Nanshan Pilot Plan (LHTD20170001)
文摘Solar energy driven photoelectrochemical(PEC) water splitting is a clean and powerful approach for renewable hydrogen production. The design and construction of metal oxide based nanoarray photoanodes is one of the promising strategies to make the continuous breakthroughs in solar to hydrogen conversion efficiency of PEC cells owing to their owned several advantages including enhanced reactive surface at the electrode/electrolyte interface, improved light absorption capability, increased charge separation efficiency and direct electron transport pathways. In this Review, we first introduce the structure,work principle and their relevant efficiency calculations of a PEC cell. We then give a summary of the state-of the-art research in the preparation strategies and growth mechanism for the metal oxide based nanoarrays, and some details about the performances of metal oxide based nanoarray photoanodes for PEC water splitting. Finally, we discuss key aspects which should be addressed in continued work on realizing high-efficiency metal oxide based nanoarray photoanodes for PEC solar water splitting systems.
基金financially supported by the National Natural Science Foundation of China (21875183, 51672210 and 51888103)the National Program for Support of Top-notch Young Professionalsthe ‘‘Fundamental Research Funds for the Central Universities”
文摘Surface treatment is an effective method to improve the photoelectrochemical(PEC) performance of photoelectrodes. Herein, we introduced a novel strategy of surface sulfurization to modify hematite(a-Fe2 O3)nanorods grown in an aqueous solution, which triggered encouraging improvement in PEC performances.In comparison to the solution-grown pristine a-Fe2 O3 nanorod photoanode that is PEC inefficient and always needs high temperature(>600 °C) activation, the surface sulfurized a-Fe2 O3 nanorods show photocurrent density increased by orders of magnitude, reaching 0.46 mA cmà2 at 1.23 V vs. RHE(reversible hydrogen electrode) under simulated solar illumination. This improvement in PEC performances should be attributed to the synergy of the increased carrier density, the reduced surface charge carrier recombination and the accelerated water oxidation kinetics at the a-Fe2 O3/electrolyte interface, as induced by the incorporation of S ions and the formation of multi-state S species(Fe-Sx-Oy) at the surface of a-Fe2 O3 nanorods. This study paves a new and facile approach to activate a-Fe2 O3 and even other metal oxides as photoelectrodes for improved PEC water splitting performances, by engineering the surface structure to relieve the bottlenecks of charge transfer dynamics and redox reaction kinetics at the electrode/electrolyte interface.
基金the financial support from Iranian Nanotechnology Society and Isfahan University of Technology (IUT) Research Council
文摘The effect of chromium doping on the photo- voltaic efficiency of dye-sensitized solar cells （DSSCs） with anodized TiO2 nanotubes followed by an annealing process was investigated. Cr-doped TiO2 nanotubes （CrTNs） with different amounts of chromium were obtained by anodizing of titanium foils in a single-step process using potassium chro- mate as the chromium source. Film features were investigated by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, energy-dispersive X-ray spectroscopy （EDX）, and ultraviolet-visible （UV-Vis） spectroscopy. It is clearly seen that highly ordered TiO2 nanotubes are formed in an anodizing solution free of potassium chromate, and with a gradual increase in the potassium chromate concentration, these nanotube structures change to nanoporous and compact films without porosity. The photovoltaic efficiencies of fabricated DSSCs were characterized by a solar cell measurement sys- tem via the photocurrent-voltage （l-V） curves. It is found that the photovoltaic efficiency of DSSCs with CrTNsl sample is improved by more than three times compared to that of DSSCs with undoped TNs. The energy conversion efficiency increases from 1.05 % to 3.89 % by doping of chromium.
文摘通过水热法成功制备了ZnO:Mg@CuWO_(4)复合材料,首先使用XRD、SEM等测试方法对各个样品进行表征,而后进行光电催化测试以确定各样品的光电催化活性。实验表明,ZnO:Mg@CuWO_(4)复合材料比纯相CuWO_(4)具有更高的光电催化活性,且与纯相ZnO:Mg相比提高了稳定性。ZnO:Mg@CuWO_(4)复合材料成功提升了光阳极的光电流密度(约0.28 mA/cm2@1.23 V vs.RHE),是纯相CuWO_(4)(约0.16 mA/cm2@1.23 V vs.RHE)光阳极的1.8倍。ZnO:Mg@CuWO_(4)复合材料提高了表面电荷注入与分离效率,促进了界面电荷的转移,减少了光生载流子复合,从而提高了CuWO_(4)的光电催化效率。
基金supported by National Natural Science Foundation of China(Grant Nos.62274143 and U22A2075)Hangzhou Joint Funds of the Zhejiang Provincial Natural Science Foundation of China(Grant No.LHZSD24E020001)+3 种基金Partial support was provided by Leading Innovative and Entrepreneur Team Introduction Program of Hangzhou(Grant No.TD2022012)Fundamental Research Funds for the Central Universities(Grant No.226-2022-00200)Natural Science Foundation of China for Innovative Research Groups(Grant No.61721005)the Open Fund of Zhejiang Provincial Key Laboratory of Wide Bandgap Semiconductors。
文摘4H silicon carbide(4H-SiC)has gained a great success in high-power electronics,owing to its advantages of wide bandgap,high breakdown electric field strength,high carrier mobility,and high thermal conductivity.Considering the high carrier mobility and high stability of 4H-SiC,4H-SiC has great potential in the field of photoelectrochemical(PEC)water splitting.In this work,we demonstrate the irradiation-resistant PEC water splitting based on nanoporous 4H-SiC arrays.A new two-step anodizing approach is adopted to prepare 4H-SiC nanoporous arrays with different porosity,that is,a constant low-voltage etching followed by a pulsed high-voltage etching.The constant-voltage etching and pulsed-voltage etching are adopted to control the diameter of the nanopores and the depth of the nanoporous arrays,respectively.It is found that the nanoporous arrays with medium porosity has the highest PEC current,because of the enhanced light absorption and the optimized transportation of charge carriers along the walls of the nanoporous arrays.The performance of the PEC water splitting of the nanoporous arrays is stable after the electron irradiation with the dose of 800 and 1600 k Gy,which indicates that 4H-SiC nanoporous arrays has great potential in the PEC water splitting under harsh environments.
基金financially supported by the National Key R&D Program of China (No. 2018YFE0208500)the National Natural Science Foundation of China (No. 41702037)
文摘Photoelectrochemical(PEC)water splitting can convert renewable solar energy into clean hydrogen fuel.Photoelectrodes are the core components of water-splitting cells.In the past 40 years,a series of binary and ternary transition metal oxides have been investigated as photo-electrode materials for solar water splitting,and numerous studies have been carried out to modify their water-split-ting performances.Although satisfactory transition metal oxide photoelectrode materials have not been found,it is necessary to summarize the recent advancements in tran-sition metal oxide photoelectrode materials to guide future research.In this review,the background and principle of PEC water splitting are introduced.The semiconductor properties and modification progress of typical binary and ternary metal oxide photoanodes and photocathodes for solar water splitting are summarized.Based on the newly developed strategies in recent years,a brief outlook is presented for efficient PEC water splitting using transition metal oxide photoelectrodes.
基金supported by the National Natural Science Foundation of China (Nos. 51572072 and 11204070)the Fundamental Research Funds for the Central Universities (No. 2014-Ia-028)financially supported by State Key Laboratory of Advanced Technology for Materials Synthesis and Processing (No. 2016-KF-13)
文摘In this work, a three-layer TiO2 composite film consisting of flower-like TiO2 （Flo-TiO2） as overlayer, TiOa nanotube arrays as interlayer and TiO2 nanoparticle （P25） as underlayer was fabricated as the photoelectrode of dyesensitized solar cells （DSSCs）. Due to the introduction of Flo-TiO2, the three-layer composite film has strong lightscattering ability. Then, we have investigated and compared the photoelectric conversion properties of DSSCs based on three-layer structure （P25/TNT arrays/Flo-TiO2） photoelectrode and double-layer film （P25/TNT arrays） photoelectrode. It is found that DSSCs based on three-layer structure exhibit a high power conversion efficiency of 6.48% compared with the DSSCs composed of double-layer film （5.11%）.
文摘近年来,基于BiVO_(4)光阳极的光电催化分解水技术引起人们的关注.我们通过水热-氨化法制备出Ni_(3)N纳米颗粒,首次将其作为助催化剂修饰到BiVO_(4)光阳极上光电催化分解水.实验表明, Ni_(3)N纳米颗粒成功负载到BiVO_(4)光阳极表面并可有效抑制表面电荷复合以及提高光电催化分解水性能.在1.23 V v. RHE处光电流密度可达3.23mA/cm^(2).此外, Ni_(3)N/BiVO_(4)光阳极的最大值ABPE值达0.88%,并呈现出良好的稳定性.
基金the financial support from Australian Research Council through its DP and FF programsthe support from Australian Government Research Training Program and UQ Centennial Scholarships
基金supported by the National Natural Science Foundation of China(Nos.51772197,51422206,51372159)the1000 Youth Talents Plan,the Key University Science Research Project of Jiangsu Province(17KJA430013)+1 种基金the 333 High-level Talents Cultivation Project of Jiangsu Province,Six Talents Peak Project of Jiangsu Province,Distinguished Young Scholars Foundation by Jiangsu Science and Technology Committee(BK20140009)Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘TiO2 photoanodes have aroused intensive research interest in photoelectrochemical （PEC） water splitting. However, they still suffer from poor electron-hole separation and sluggish oxygen evolution dynamics, leading to the low photoconversion efficiency and limiting commercial application. Here, we designed and fabricated novel ternary non-noble metal carbonate hydroxide （ZNC-CH） nanosheet cocatalysts and integrated them with TiO2 nanorod arrays as highly efficient photoanodes of PEC cells. Compared with the pristine TiO2, the photocurrent of photoanode with the optimal amount of ZNC-CH represents 3.2 times enhancement, and the onset potential is shifted toward the negative potential direction of 62 mV, The remarkable enhancement is attributed to the suppressed carrier recombination and enhanced charge transfer efficiency at the interface of TiO2, ZNC-CH and electrolyte, which is closely related to the zinc elements modulated intrinsic activity of catalysts. Our results demonstrate that the introduction of multimetallic ZNC-CH cocatalysts onto photoanodes is a promising strategy to improve the PEC efficiency.
文摘Z-scheme photocatalytic system has been regarded as a popular field of research in photoelectrochemical(PEC)water splitting.Among the many obstacles facing a Z-scheme photocatalytic system,the analysis methods of interfacial Z-scheme charge transfer still remain a significant challenge.Hence,in this study,CdS/Ti-Fe_(2)O_(3)heterojunction photoanodes are elaborately designed to explore the charge-transfer behavior in PEC water splitting.In this study,photophysical measurements,including the Kelvin probe measurement,surface photovoltage spectroscopy(SPV),and transient photovoltage spectroscopy(TPV),are used to monitor the migration behavior of photogenerated charges at the interface electric field of CdS/Ti-Fe_(2)O_(3)Z-scheme heterojunction photoanodes.The Kelvin probe and SPV measurements demonstrate that CdS/Ti-Fe_(2)O_(3)interfacial driving force favors the rapid transfer of photoexcited electrons to CdS.The double-beam strategy based on TPV indicates that more electrons of Ti-Fe_(2)O_(3)are combined with the holes of CdS owing to the intensive interface electric field.The results of these measurements successfully prove the Z-scheme migration mechanism of CdS/Ti-Fe_(2)O_(3)photoanodes.Benefiting from the desirable charge transfer at the interface electric field,CdS/Ti-Fe_(2)O_(3)photoanodes exhibit superior photocatalytic oxygen evolution reaction performance compared with that of pure Ti-Fe_(2)O_(3).The photocurrent density of the 25CdS/Ti-Fe_(2)O_(3)photoanode reaches 1.94 mA/cm^(2) at 1.23 V versus reversible hydrogen electrode without excess cocatalyst,and it is two times higher than that of pure Ti-Fe_(2)O_(3)photoanode.Therefore,an outstanding strategy is provided in this study to prove the Z-scheme charge-transfer mechanism of photocatalytic systems in PEC water splitting.
文摘通过滴涂法成功制备了Bi_(2)WO_(6)/Fe_(2)O_(3)复合材料,利用XRD、SEM等方法进行表征和一系列光电催化测试。结果表明,Bi_(2)WO_(6)/Fe_(2)O_(3)复合材料比纯相Fe_(2)O_(3)具有更好的催化活性,且滴涂10μL Bi_(2)WO_(6)前驱体溶液的Bi_(2)WO_(6)/Fe_(2)O_(3)光阳极具有最高的光电流密度(0.15 mA·cm^(-2)@1.23 V vs.RHE),是纯相Fe_(2)O_(3)(约4.4μA·cm^(-2)@1.23 V vs.RHE)光电阳极的34倍。复合材料的形成增加了吸收光谱范围,提高了对可见光的利用率,促进了界面电荷转移,抑制了光生载流子复合,从而提高了Fe_(2)O_(3)的光电催化活性。
