Highly active and stable FeOOH cocatalysts are essential for achieving optimal performance of BiVO_(4)(BVO)photoanodes.Despite offering remarkable structural stability,widely used thick FeOOH cocatalysts often suffer ...Highly active and stable FeOOH cocatalysts are essential for achieving optimal performance of BiVO_(4)(BVO)photoanodes.Despite offering remarkable structural stability,widely used thick FeOOH cocatalysts often suffer from insufficient hole transport capability,which hinders the overall activity.The present study demonstrates that a simple photoetching strategy is able to introduce gradient distributed oxygen vacancies(GO_(V))in the thick FeOOH layer and significantly enhances the photogenerated holes transport dynamics.The incorporation of GO_(V)within FeOOH not only realizes the“relay transport”of photogenerated hole through the progressive upward shift of the valence band in the spatial distribution,but also provides abundant oxidation active sites by efficient hole trapping.These improvements effectively improve the oxygen evolution reaction(OER)activities and mitigate photocorrosion by the instantaneous hole extraction.Consequently,the FeOOH-GO_(V)layer enables the BVO/FeOOH-GO_(V)photoanode to achieve an impressive photocurrent density of 5.37 mA cm^(-2)and a robust operational stability up to 160 h at 1.23 VRHE,setting new benchmarks for current density and stability in FeOOH-based BVO photoanodes.This work provides an effective avenue to optimize OER cocatalysts for constructing highly efficient and stable photoelectrochemical water splitting devices.展开更多
The limited material removal rate of conventional chemical mechanical polishing(CMP)significantly hinders the fabrica-tion efficiency and surface quality,thereby preventing the development of gallium nitride(GaN)-base...The limited material removal rate of conventional chemical mechanical polishing(CMP)significantly hinders the fabrica-tion efficiency and surface quality,thereby preventing the development of gallium nitride(GaN)-based devices.Moreover,the incorporation of photoelectrochemistry in CMP has garnered increasing attention because of its potential to enhance the quality and efficiency of the GaN process.However,a considerable gap still exists in the comprehensive understanding of the specific photoelectrochemical(PEC)behavior of GaN.Here,we report the influence of the electrolyte on the PEC etching of GaN.Various acids and bases were tested,with their pH being carefully adjusted.The concentrations of the cations and anions were also examined.The results showed that photocorrosion/photoetching was more pronounced in sulfuric acid,phosphoric acid,and nitric acid environments than in alkaline environments,but it was less pronounced in hydrochloric acid.Furthermore,the effects of pH and anion concentration on photoetching were investigated,and the results revealed that pho-toetching in acidic environments weakened with increasing pH levels and diminished with increasing sulfate concentration.The underlying reasons contributing to this observation were explored.These findings provide ideas for improving the pho-toetching efficiency of GaN,thereby enriching the photoelectrochemical mechanical polishing(PECMP)technology of GaN.展开更多
Photoelectrochemical(PEC)water-splitting using solar energy holds great promise for the renewable energy future,and a key challenge in the development of industry viable PEC devices is the unavailability of high-effic...Photoelectrochemical(PEC)water-splitting using solar energy holds great promise for the renewable energy future,and a key challenge in the development of industry viable PEC devices is the unavailability of high-efficient photoanodes.Herein,we designed a TiO_(2) model photocatalyst with nano-groove pattern and different surface orientation using low-energy Ar+irradiation and photoetching of TiO_(2),and significantly improved the intrinsic activity for PEC water oxidation.High-resolution transmission electron microscopy directly manifests that the grooves consist of highly stepped surface with<110>steps and well-crystallized.Transient absorption spectroscopy reveals the groove surface that allows for increased recovery lifetime,which ensures promoted electron-hole separation efficiency.Surface photovoltage directly shows the carrier separation and transportation behaviors,verified by selective photodeposition,demonstrating the groove surface on TiO_(2) contributes to electron-hole separation.This work proposes an efficient and scalable photoanode strategy,which potentially can open new opportunities for achieving efficient PEC water oxidation performance.展开更多
基金supported by the State Key Laboratory of Solidification Processing in NWPU(SKLSP202407)the National Natural Science Foundation of China(52402130)+2 种基金the Natural Science Basis Research Plan in Shaanxi Province of China(2024JC-YBQN-0384)the Shaanxi Science and Technology Innovation Team(2023-CX-TD-44)the National Natural Science Foundation of China(52301015).
文摘Highly active and stable FeOOH cocatalysts are essential for achieving optimal performance of BiVO_(4)(BVO)photoanodes.Despite offering remarkable structural stability,widely used thick FeOOH cocatalysts often suffer from insufficient hole transport capability,which hinders the overall activity.The present study demonstrates that a simple photoetching strategy is able to introduce gradient distributed oxygen vacancies(GO_(V))in the thick FeOOH layer and significantly enhances the photogenerated holes transport dynamics.The incorporation of GO_(V)within FeOOH not only realizes the“relay transport”of photogenerated hole through the progressive upward shift of the valence band in the spatial distribution,but also provides abundant oxidation active sites by efficient hole trapping.These improvements effectively improve the oxygen evolution reaction(OER)activities and mitigate photocorrosion by the instantaneous hole extraction.Consequently,the FeOOH-GO_(V)layer enables the BVO/FeOOH-GO_(V)photoanode to achieve an impressive photocurrent density of 5.37 mA cm^(-2)and a robust operational stability up to 160 h at 1.23 VRHE,setting new benchmarks for current density and stability in FeOOH-based BVO photoanodes.This work provides an effective avenue to optimize OER cocatalysts for constructing highly efficient and stable photoelectrochemical water splitting devices.
基金support from the Shenzhen Key Laboratory of Intelligent Robotics and Flexible Manufacturing Systems(ZDSYS20220527171403009)the valuable technical support provided by the SUSTech Core Research Facilities and the SUSTech Energy Research Institute for Carbon Neutrality.Special thanks are given to Thermo Fisher for their technical support during the in situ Raman experiments.
文摘The limited material removal rate of conventional chemical mechanical polishing(CMP)significantly hinders the fabrica-tion efficiency and surface quality,thereby preventing the development of gallium nitride(GaN)-based devices.Moreover,the incorporation of photoelectrochemistry in CMP has garnered increasing attention because of its potential to enhance the quality and efficiency of the GaN process.However,a considerable gap still exists in the comprehensive understanding of the specific photoelectrochemical(PEC)behavior of GaN.Here,we report the influence of the electrolyte on the PEC etching of GaN.Various acids and bases were tested,with their pH being carefully adjusted.The concentrations of the cations and anions were also examined.The results showed that photocorrosion/photoetching was more pronounced in sulfuric acid,phosphoric acid,and nitric acid environments than in alkaline environments,but it was less pronounced in hydrochloric acid.Furthermore,the effects of pH and anion concentration on photoetching were investigated,and the results revealed that pho-toetching in acidic environments weakened with increasing pH levels and diminished with increasing sulfate concentration.The underlying reasons contributing to this observation were explored.These findings provide ideas for improving the pho-toetching efficiency of GaN,thereby enriching the photoelectrochemical mechanical polishing(PECMP)technology of GaN.
基金support from the Ministry of Science and Technology of China (No. 2016YFA0202803 and 2018YFA0704503)the National Natural Science Foundation of China (21991152,21991150, 21802096, 21832004, 21902179 and 22072093)+2 种基金the Shanghai-XFEL Beamline Project (SBP) (no. 31011505505885920161A2101001)supported by ME2 project under contract No.11227902 from National Natural Science Foundation of Chinasupport of Shanghai Sailing Program (No. 19YF1455600)。
文摘Photoelectrochemical(PEC)water-splitting using solar energy holds great promise for the renewable energy future,and a key challenge in the development of industry viable PEC devices is the unavailability of high-efficient photoanodes.Herein,we designed a TiO_(2) model photocatalyst with nano-groove pattern and different surface orientation using low-energy Ar+irradiation and photoetching of TiO_(2),and significantly improved the intrinsic activity for PEC water oxidation.High-resolution transmission electron microscopy directly manifests that the grooves consist of highly stepped surface with<110>steps and well-crystallized.Transient absorption spectroscopy reveals the groove surface that allows for increased recovery lifetime,which ensures promoted electron-hole separation efficiency.Surface photovoltage directly shows the carrier separation and transportation behaviors,verified by selective photodeposition,demonstrating the groove surface on TiO_(2) contributes to electron-hole separation.This work proposes an efficient and scalable photoanode strategy,which potentially can open new opportunities for achieving efficient PEC water oxidation performance.
