Intergrowth ferroelectric semiconductors with excellent spontaneous polarization field are highly promising piezo-photocatalytic candidate materials.In addition,developing structural design and revealing polarization ...Intergrowth ferroelectric semiconductors with excellent spontaneous polarization field are highly promising piezo-photocatalytic candidate materials.In addition,developing structural design and revealing polarization enhancement in-depth mechanism are top priorities.Herein,we introduce the intergrowth ferroelectrics Bi_(7)Ti_(4)NbO_(21)thin-layer nanosheets for piezo-photocatalytic CO_(2)reduction.Density functional theory(DFT)calculations indicate that interlayer lattice mismatch leads to increased tilting and rotation angle of Ti/NbO_(6)octahedra on perovskite-like layers,serving as the main reason for increased polarization.Furthermore,the tilting and rotation angle of the interlayer octahedron further increase under stress,suggesting a stronger driving force generated to facilitate charge carrier separation efficiency.Meanwhile,Bi_(7)Ti_(4)NbO_(21)nanosheets provide abundant active sites to effectively adsorb CO_(2)and acquire sensitive stress response,thereby presenting synergistically advanced piezo-photocatalytic CO_(2)reduction activity with a high CO generation rate of 426.97μmol g^(-1)h^(-1).Our work offers new perspectives and directions for initiating and investigating the mechanisms of high-performance intergrowth piezo-photocatalysts.展开更多
Organofluorine compounds have consistently played a pivotal role in chemical synthesis,materials development,and drug discovery.Among these,chiral organofluorine compounds have emerged as a significant focus of resear...Organofluorine compounds have consistently played a pivotal role in chemical synthesis,materials development,and drug discovery.Among these,chiral organofluorine compounds have emerged as a significant focus of research.Gem-difluoroalkenes and difluoroenoxysilanes,owing to their high reactivity and modifiability,are extensively employed in the synthesis of chiral organofluorine compounds.This review summarizes recent research progress in the use of these molecules in asymmetric synthesis.Their application in synthesizing biologically active chiral molecules could open new possibilities and lead to unexpected breakthroughs in medicinal chemistry.展开更多
Piezocatalysis has emerged as promising technique for production of hydrogen peroxide(H_(2)O_(2))and wastewater treatment;however,slow reaction kinetics significantly hinder its efficiency.This work presents an effect...Piezocatalysis has emerged as promising technique for production of hydrogen peroxide(H_(2)O_(2))and wastewater treatment;however,slow reaction kinetics significantly hinder its efficiency.This work presents an effective strategy wherein we constructed amorphous ZnCdS and bismuth titanate with oxygen vacancies heterostructure(A-ZnCdS/Bi_(4)Ti_(3)O_(12)-Ov,denoted as AZCS/BTO-Ov)to facilitate in-situ H_(2)O_(2)evolution and establish piezocatalytic coupled Fenton(PCF)-like reaction system for efficient wastewater purification.Notably,H_(2)O_(2)evolution rate from AZCS/BTO-Ov catalyst reaches 1172.3μmol g^(−1)h^(−1)in pure water,greatly surpassing the rates observed for pure BTO-Ov and AZCS.Furthermore,evolution rate increases to 2300.2μmol g^(−1)h^(−1)upon addition of ethanol as sacrificial agent,demonstrating excellent activity.Within PCF-like reaction system(AZCS/BTO-Ov/Fe^(2+)),particularly degradation efficiency of methyl orange dye reaches 92.9%within 16 min,accompanied by high kinetic coefficient of 0.171 min^(−1),indicating exceptional catalytic activity that exceeds that of most other piezocatalysts.Relevant experimental results and density functional theory calculations unravel the reaction mechanism,demonstrating that the excellent piezocatalytic performances of AZCS/BTO-Ov are primarily attributed to the construction of heterostructure by significantly modulating electronic structure,improving separation efficiency of charge carriers,facilitating reaction dynamics,and activating both O2 and H2O.This research promotes in-situ synthesis of valuable chemicals and provides sustainable and cost-effective pathway to environmental remediation.展开更多
Defect modulation currently plays a decisive role in addressing the poor photoabsorption,sluggish electron hole separation,and high CO_(2)activation barrier in photocatalytic CO_(2)reduction.However,hunting for a stra...Defect modulation currently plays a decisive role in addressing the poor photoabsorption,sluggish electron hole separation,and high CO_(2)activation barrier in photocatalytic CO_(2)reduction.However,hunting for a straightforward strategy to balance the concentration of oxygen vacancy and metal cation defect in one photocatalyst is still a great challenge.Herein,a bismuth vacancies BiOBr nanosheets(BiOBr-1)on the exposed[001]facets were constructed via an acetic acid molecule modification strategy,which can repair oxygen defect by bismuth vacancy in low-temperature solid-state chemical method.Benefiting from the formed bismuth defects that can not only broaden light absorption and elevate charge separation efficiency,but also enhance adsorption and activation of CO_(2)molecules,the evolution rates of photocatalytic CO_(2)conversion into CO(71.23μmol·g^(-1)·h^(-1))and CH4(8.90μmol·g^(-1)·h^(-1))attained by BiOBr-1 are superior 7.1 and 11 times to that of plate-like BiOBr.The photocatalytic mechanisms including adsorption concentration and activation process of CO_(2)are further revealed by the in situ diffuse reflectance infrared flourier transform spectra(DRIFTS).This finding of the existence of distinct defects in ultrathin nanosheets undoubtedly leads to new possibilities for photocatalyst design using two-dimensional materials with high solar-driven photocatalytic activity.展开更多
The hunt for novel methods and nanomaterials with suitable band gaps is a critical hindrance to the rational design of Z-scheme heterogeneous junctions,which simultaneously improve the charge transfer efficiency and m...The hunt for novel methods and nanomaterials with suitable band gaps is a critical hindrance to the rational design of Z-scheme heterogeneous junctions,which simultaneously improve the charge transfer efficiency and maintain high redox activity.In this study,a Z-scheme carrier migration system was constructed by uniformly loading carbonized polymer dots on BiOBr nanosheets(CPDs/BiOBr)through a low-heating solid-state chemical reaction.Without the addition of a sacrificial agent or photosensitizer,the photocatalytic reduction rate of a 6 wt%CPDs/BiOBr heterojunction was 144.6μmol g^(−1) h^(−1),which is 2.02 times higher than that of pure BiOBr.The excellent photocatalytic performance of the 6 wt%CPDs/BiOBr composite was attributed to the Z-scheme heterojunction,which can maintain the redox ability of the material and promote the rapid separation of photogenerated carriers.Besides,the up-conversion characteristics of CPDs can broaden the scope of light absorption.This study provides a clear understanding of the role of carbon-based quantum dots in the design of efficient Z-scheme photocatalysts for CO_(2) reduction.展开更多
Transition metal oxides(TMOs)are considered promising anode materials for lithium-ion batteries(LIBs)because of their high theoretical capacity.However,their use in LIBs is limited by factors such as low initial coulo...Transition metal oxides(TMOs)are considered promising anode materials for lithium-ion batteries(LIBs)because of their high theoretical capacity.However,their use in LIBs is limited by factors such as low initial coulombic efficiency,substantial volume changes,and low electrical conductivity.Here,amorphous MoO_(2) capped with different carbon sources is ingeniously designed by controlling the calcination temperature and different carbon sources.Electrochemical kinetics and material characterization show that the amorphous structure not only enhances its electronic conductivity,but also optimizes the lithium-ion(Li+)migration mode,thus improving its rate performance.Furthermore,the pore sizes produced by different carbon sources were found to have different effects on the performance of LIBs.Meanwhile,the Li+storage mechanism of the amorphous MoO_(2)-x@C was revealed by in-situ XRD analysis.As expected,the amorphous MoO_(2)-x@C exhibits excellent cycling stability,maintaining a discharge specific capacity of 601.4 mA h g^(-1) at 5.0 A g^(-1) for 800 cycles.In particular,the MoO_(2)-x@C||LiCoO_(2) full cell still possesses a capacity of 109.8 mA h g^(-1) at 0.2 C for 80 cycles.This endeavor will provide an experimental idea for molybdenum-based oxide high-performance anode materials.展开更多
基金support from the Natural Science Foundation of Jiangsu Province(BK20220596)Innovative science and technology platform project of cooperation between Yangzhou City and Yangzhou University,China(No.YZ202026305)+1 种基金Natural Science Foundation of China(21922202,21673202 and 22272147)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Intergrowth ferroelectric semiconductors with excellent spontaneous polarization field are highly promising piezo-photocatalytic candidate materials.In addition,developing structural design and revealing polarization enhancement in-depth mechanism are top priorities.Herein,we introduce the intergrowth ferroelectrics Bi_(7)Ti_(4)NbO_(21)thin-layer nanosheets for piezo-photocatalytic CO_(2)reduction.Density functional theory(DFT)calculations indicate that interlayer lattice mismatch leads to increased tilting and rotation angle of Ti/NbO_(6)octahedra on perovskite-like layers,serving as the main reason for increased polarization.Furthermore,the tilting and rotation angle of the interlayer octahedron further increase under stress,suggesting a stronger driving force generated to facilitate charge carrier separation efficiency.Meanwhile,Bi_(7)Ti_(4)NbO_(21)nanosheets provide abundant active sites to effectively adsorb CO_(2)and acquire sensitive stress response,thereby presenting synergistically advanced piezo-photocatalytic CO_(2)reduction activity with a high CO generation rate of 426.97μmol g^(-1)h^(-1).Our work offers new perspectives and directions for initiating and investigating the mechanisms of high-performance intergrowth piezo-photocatalysts.
基金support from the Sichuan University of Science&Engineering(2024RC042)and HKBU RC-SFCRG/23-24 for financial support.
文摘Organofluorine compounds have consistently played a pivotal role in chemical synthesis,materials development,and drug discovery.Among these,chiral organofluorine compounds have emerged as a significant focus of research.Gem-difluoroalkenes and difluoroenoxysilanes,owing to their high reactivity and modifiability,are extensively employed in the synthesis of chiral organofluorine compounds.This review summarizes recent research progress in the use of these molecules in asymmetric synthesis.Their application in synthesizing biologically active chiral molecules could open new possibilities and lead to unexpected breakthroughs in medicinal chemistry.
基金the National Natural Science Foundation of China(No.12064042)Talent Introduction Project of Sichuan University of Science and Engineering(No.2024RC044)+1 种基金Salt City Millions of Talents Program-Leading Team(No.H8012001)Scientific Research and Innovation Team Program of Sichuan University of Science and Technology(No.SUSE652A003).
文摘Piezocatalysis has emerged as promising technique for production of hydrogen peroxide(H_(2)O_(2))and wastewater treatment;however,slow reaction kinetics significantly hinder its efficiency.This work presents an effective strategy wherein we constructed amorphous ZnCdS and bismuth titanate with oxygen vacancies heterostructure(A-ZnCdS/Bi_(4)Ti_(3)O_(12)-Ov,denoted as AZCS/BTO-Ov)to facilitate in-situ H_(2)O_(2)evolution and establish piezocatalytic coupled Fenton(PCF)-like reaction system for efficient wastewater purification.Notably,H_(2)O_(2)evolution rate from AZCS/BTO-Ov catalyst reaches 1172.3μmol g^(−1)h^(−1)in pure water,greatly surpassing the rates observed for pure BTO-Ov and AZCS.Furthermore,evolution rate increases to 2300.2μmol g^(−1)h^(−1)upon addition of ethanol as sacrificial agent,demonstrating excellent activity.Within PCF-like reaction system(AZCS/BTO-Ov/Fe^(2+)),particularly degradation efficiency of methyl orange dye reaches 92.9%within 16 min,accompanied by high kinetic coefficient of 0.171 min^(−1),indicating exceptional catalytic activity that exceeds that of most other piezocatalysts.Relevant experimental results and density functional theory calculations unravel the reaction mechanism,demonstrating that the excellent piezocatalytic performances of AZCS/BTO-Ov are primarily attributed to the construction of heterostructure by significantly modulating electronic structure,improving separation efficiency of charge carriers,facilitating reaction dynamics,and activating both O2 and H2O.This research promotes in-situ synthesis of valuable chemicals and provides sustainable and cost-effective pathway to environmental remediation.
基金supported by the National Natural Science Foundation of China(No.52162023)the Natural Science Foundation of Xinjiang Autonomous Region(No.2021D01C093)+1 种基金the Xinjiang Tianchi Doctoral Project(No.TCBS201933)the Xinjiang University Doctoral Research Foundation(No.BS190228).
文摘Defect modulation currently plays a decisive role in addressing the poor photoabsorption,sluggish electron hole separation,and high CO_(2)activation barrier in photocatalytic CO_(2)reduction.However,hunting for a straightforward strategy to balance the concentration of oxygen vacancy and metal cation defect in one photocatalyst is still a great challenge.Herein,a bismuth vacancies BiOBr nanosheets(BiOBr-1)on the exposed[001]facets were constructed via an acetic acid molecule modification strategy,which can repair oxygen defect by bismuth vacancy in low-temperature solid-state chemical method.Benefiting from the formed bismuth defects that can not only broaden light absorption and elevate charge separation efficiency,but also enhance adsorption and activation of CO_(2)molecules,the evolution rates of photocatalytic CO_(2)conversion into CO(71.23μmol·g^(-1)·h^(-1))and CH4(8.90μmol·g^(-1)·h^(-1))attained by BiOBr-1 are superior 7.1 and 11 times to that of plate-like BiOBr.The photocatalytic mechanisms including adsorption concentration and activation process of CO_(2)are further revealed by the in situ diffuse reflectance infrared flourier transform spectra(DRIFTS).This finding of the existence of distinct defects in ultrathin nanosheets undoubtedly leads to new possibilities for photocatalyst design using two-dimensional materials with high solar-driven photocatalytic activity.
基金supported by the National Natural Science Foundation of China(no.52162023)the Natural Science Foundation of Xinjiang Autonomous Region(no.2021D01C093)+1 种基金the Xinjiang Tianchi Doctoral Project(no.TCBS201933)the Xinjiang University Doctoral Research Foundation(no.BS190228).
文摘The hunt for novel methods and nanomaterials with suitable band gaps is a critical hindrance to the rational design of Z-scheme heterogeneous junctions,which simultaneously improve the charge transfer efficiency and maintain high redox activity.In this study,a Z-scheme carrier migration system was constructed by uniformly loading carbonized polymer dots on BiOBr nanosheets(CPDs/BiOBr)through a low-heating solid-state chemical reaction.Without the addition of a sacrificial agent or photosensitizer,the photocatalytic reduction rate of a 6 wt%CPDs/BiOBr heterojunction was 144.6μmol g^(−1) h^(−1),which is 2.02 times higher than that of pure BiOBr.The excellent photocatalytic performance of the 6 wt%CPDs/BiOBr composite was attributed to the Z-scheme heterojunction,which can maintain the redox ability of the material and promote the rapid separation of photogenerated carriers.Besides,the up-conversion characteristics of CPDs can broaden the scope of light absorption.This study provides a clear understanding of the role of carbon-based quantum dots in the design of efficient Z-scheme photocatalysts for CO_(2) reduction.
基金supported by the Central Government Guides Local Scientific and Technological Development Projects of the Xinjiang Autonomous Region(No.ZYYD2023A05)the Natural Science Foundation of the Xinjiang Autonomous Region(No.2021D01C098)the National Natural Science Foundation of China(No.22278348).
文摘Transition metal oxides(TMOs)are considered promising anode materials for lithium-ion batteries(LIBs)because of their high theoretical capacity.However,their use in LIBs is limited by factors such as low initial coulombic efficiency,substantial volume changes,and low electrical conductivity.Here,amorphous MoO_(2) capped with different carbon sources is ingeniously designed by controlling the calcination temperature and different carbon sources.Electrochemical kinetics and material characterization show that the amorphous structure not only enhances its electronic conductivity,but also optimizes the lithium-ion(Li+)migration mode,thus improving its rate performance.Furthermore,the pore sizes produced by different carbon sources were found to have different effects on the performance of LIBs.Meanwhile,the Li+storage mechanism of the amorphous MoO_(2)-x@C was revealed by in-situ XRD analysis.As expected,the amorphous MoO_(2)-x@C exhibits excellent cycling stability,maintaining a discharge specific capacity of 601.4 mA h g^(-1) at 5.0 A g^(-1) for 800 cycles.In particular,the MoO_(2)-x@C||LiCoO_(2) full cell still possesses a capacity of 109.8 mA h g^(-1) at 0.2 C for 80 cycles.This endeavor will provide an experimental idea for molybdenum-based oxide high-performance anode materials.
