Semiconductor-based solar-driven water splitting technology is an environmentally friendly and cost-effective approach for the production of clean fuels.The overall solar-to-hydrogen efficiency of semiconductorbased p...Semiconductor-based solar-driven water splitting technology is an environmentally friendly and cost-effective approach for the production of clean fuels.The overall solar-to-hydrogen efficiency of semiconductorbased photo(electro)catalysts is jointly determined by factors,such as light absorption efficiency of the photo(electro)catalysts,internal separation efficiency of charge carriers,and injection efficiency of surface charges.However,the traditional improvement strategies,such as morphology control,functional layer modification,and band alignment engineering,still have certain limitations in enhancing the conversion efficiency of the photo(electro)catalytic water splitting.Recently,unconventional enhancement strategies based on surface plasmonic effects,piezoelectric effects,thermoelectric effects,and magnetic effects have provided unique pathways for improving the solar-to-hydrogen efficiency of photo(electro)catalysts.Therefore,this review outlines the fundamental concepts of these physical effects and elucidates their intrinsic mechanisms in enhancing the efficiency of photo(electro)catalysts for water splitting process through practical application examples.Ultimately,the future development of unconventional strategies for enhancing photo(electro)catalytic water splitting is envisioned.展开更多
Introducing and stabilizing twins in aluminum is a challenge for metals research due to their high formation energy.Employing first-principles calculations,we investigated the twin boundary segregation of alloying ele...Introducing and stabilizing twins in aluminum is a challenge for metals research due to their high formation energy.Employing first-principles calculations,we investigated the twin boundary segregation of alloying elements and their impact on the twin boundary energy in aluminum.Alloying elements with small solubilities but strong interaction with twin boundary would significantly reduce twin boundary energies in aluminum at low temperatures.With increasing temperature,their segregation near twin boundary weakens,leading to their influence on twin boundary energies reduced.Some elements with large solubilities may greatly reduce the twin energies not only at low temperatures but also at high temperatures.Based on careful analysis of charge density and atomic radius,it has been found that chemical difference has little influence on twin boundary energy whereas the atomic size effect plays a leading role in causing the change of twin boundary energy.展开更多
Acetone is an important industrial raw material as well as biomarker in medical diagnosis.The detection of acetone has great significance for safety and health.However,high selectivity and low concentration(ppb level)...Acetone is an important industrial raw material as well as biomarker in medical diagnosis.The detection of acetone has great significance for safety and health.However,high selectivity and low concentration(ppb level)detection remain challenges for semiconductor gas sensor.Herein,we present a novel sensitive material with bimetallic PtCu nanocrystal modified on WO3·H2O hollow spheres(HS),which shows high sensitivity,excellent selectivity,fast response/recovery speed and low limit of detection(LOD)to acetone detection.Noteworthy,the response(Ra/Rg)of WO3·H2O HS sensor increased by 9.5 times after modification with 0.02%bimetallic PtCu nanocrystals.The response of PtCu/WO3·H2O HS to 50 ppm acetone is as high as 204.9 with short response/recovery times(3.4 s/7.5 s).Finally,the gassensitivity mechanism was discussed based on gas sensitivity test results.This research will offer a new route for high efficient acetone detection.展开更多
Ni-rich layered lithium transition metal oxides LiNi_xMn_yCo_zO_(2)(1-y-z≥0.6)are promising candidates for cathode materials,but their practical applications are hindered by high-voltage instability and fast capacity...Ni-rich layered lithium transition metal oxides LiNi_xMn_yCo_zO_(2)(1-y-z≥0.6)are promising candidates for cathode materials,but their practical applications are hindered by high-voltage instability and fast capacity fading.Using density functional theory calculations,we demonstrate that Na-,F-doping,and Na/F-co-doping can stabilize the structure and result into a higher open circuit voltage than pristine LiNi_(0.6)Mn_(0.2)Co_(0.2)O_(2)(NMC622)during the charging process,which may attain greater discharge capacity.F doping may inhibit the diffusion of Li ions at the beginning and end of charging;Na doping may improve Li ion diffusion due to the increase in Li layer spacing,consistent with prior experiments.Na/F-codoping into NMC622 promotes rate performance and reduces irreversible phase transitions for two reasons:(i)a synergistic effect between Na and F can effectively restrain the Ni/Li mixing and then enhances the mobility of Li ions and(ii)Ni/Li mixing hinders the Ni ions to migrate into Li layers and thus,stabilizes the structure.This study proposes that a layer cathode material with high electrochemical performance can be achieved via rational dopant modification,which is a promising strategy for designing efficient Li ion batteries.展开更多
基金Research start-up funding in Yangtze Delta Region Institute of UESTC,Grant/Award Numbers:U03220088,U03220089,U032200106,U032200107Young Leading Talents of Nantaihu Talent Program in Huzhou(2022)。
文摘Semiconductor-based solar-driven water splitting technology is an environmentally friendly and cost-effective approach for the production of clean fuels.The overall solar-to-hydrogen efficiency of semiconductorbased photo(electro)catalysts is jointly determined by factors,such as light absorption efficiency of the photo(electro)catalysts,internal separation efficiency of charge carriers,and injection efficiency of surface charges.However,the traditional improvement strategies,such as morphology control,functional layer modification,and band alignment engineering,still have certain limitations in enhancing the conversion efficiency of the photo(electro)catalytic water splitting.Recently,unconventional enhancement strategies based on surface plasmonic effects,piezoelectric effects,thermoelectric effects,and magnetic effects have provided unique pathways for improving the solar-to-hydrogen efficiency of photo(electro)catalysts.Therefore,this review outlines the fundamental concepts of these physical effects and elucidates their intrinsic mechanisms in enhancing the efficiency of photo(electro)catalysts for water splitting process through practical application examples.Ultimately,the future development of unconventional strategies for enhancing photo(electro)catalytic water splitting is envisioned.
基金supported financially by the National Natural Science Foundation of China (Nos.51701243,11427806,51471067 and 51371081)the Hunan Provincial Natural Science Foundation of China (No.2019JJ40544)+3 种基金the Specialized Research Found for the Doctoral Program of Higher Education of China (No. 20120161110036)the National Basic Research (973) Program of China (No.2009CB623704)the PhD Research Startup Foundation of Central South University of Forestry and Technology (No. 2017YJ020)the supercomputer TH-1A installed at Hunan University
文摘Introducing and stabilizing twins in aluminum is a challenge for metals research due to their high formation energy.Employing first-principles calculations,we investigated the twin boundary segregation of alloying elements and their impact on the twin boundary energy in aluminum.Alloying elements with small solubilities but strong interaction with twin boundary would significantly reduce twin boundary energies in aluminum at low temperatures.With increasing temperature,their segregation near twin boundary weakens,leading to their influence on twin boundary energies reduced.Some elements with large solubilities may greatly reduce the twin energies not only at low temperatures but also at high temperatures.Based on careful analysis of charge density and atomic radius,it has been found that chemical difference has little influence on twin boundary energy whereas the atomic size effect plays a leading role in causing the change of twin boundary energy.
基金the financial supports from the National Natural Science Foundation of China(Nos.51702212,51802195,31701678,61671284)Science and Technology Commission of Shanghai Municipality(Nos.18511110600,19ZR1435200)+1 种基金Innovation Program of Shanghai Municipal Education Commission(No.2019-01-07-00-07-E00015)Program of Shanghai Academic Research Leader(No.19XD1422900)。
文摘Acetone is an important industrial raw material as well as biomarker in medical diagnosis.The detection of acetone has great significance for safety and health.However,high selectivity and low concentration(ppb level)detection remain challenges for semiconductor gas sensor.Herein,we present a novel sensitive material with bimetallic PtCu nanocrystal modified on WO3·H2O hollow spheres(HS),which shows high sensitivity,excellent selectivity,fast response/recovery speed and low limit of detection(LOD)to acetone detection.Noteworthy,the response(Ra/Rg)of WO3·H2O HS sensor increased by 9.5 times after modification with 0.02%bimetallic PtCu nanocrystals.The response of PtCu/WO3·H2O HS to 50 ppm acetone is as high as 204.9 with short response/recovery times(3.4 s/7.5 s).Finally,the gassensitivity mechanism was discussed based on gas sensitivity test results.This research will offer a new route for high efficient acetone detection.
基金the National Natural Science Foundation of China(Grant Nos.51802092 and 51771073)the Fundamental Research Funds for the Central Universities.China。
文摘Ni-rich layered lithium transition metal oxides LiNi_xMn_yCo_zO_(2)(1-y-z≥0.6)are promising candidates for cathode materials,but their practical applications are hindered by high-voltage instability and fast capacity fading.Using density functional theory calculations,we demonstrate that Na-,F-doping,and Na/F-co-doping can stabilize the structure and result into a higher open circuit voltage than pristine LiNi_(0.6)Mn_(0.2)Co_(0.2)O_(2)(NMC622)during the charging process,which may attain greater discharge capacity.F doping may inhibit the diffusion of Li ions at the beginning and end of charging;Na doping may improve Li ion diffusion due to the increase in Li layer spacing,consistent with prior experiments.Na/F-codoping into NMC622 promotes rate performance and reduces irreversible phase transitions for two reasons:(i)a synergistic effect between Na and F can effectively restrain the Ni/Li mixing and then enhances the mobility of Li ions and(ii)Ni/Li mixing hinders the Ni ions to migrate into Li layers and thus,stabilizes the structure.This study proposes that a layer cathode material with high electrochemical performance can be achieved via rational dopant modification,which is a promising strategy for designing efficient Li ion batteries.
