Elemental doping of BiVO_(4) crystal lattices effectively enhances carrier separation,thereby facilitating efficient photoelectrochemical water splitting.However,the positive effect of elementally induced lattice dist...Elemental doping of BiVO_(4) crystal lattices effectively enhances carrier separation,thereby facilitating efficient photoelectrochemical water splitting.However,the positive effect of elementally induced lattice distortions on hole extraction has been neglected.Herein,the crystal lattice of BiVO_(4) is distorted by doping with an inexpensive Cs metal;then,CoFe_(2)O_(4) is used as an efficient hole-extraction layer to further modify the surface of the doped photoanode.Benefiting from the above design,the newly prepared CoFe_(2)O_(4)-Cs-BiVO_(4) photoanode achieved a photocurrent density of 5.66 mA cm^(–2) at 1.23 V vs.a reversible hydrogen electrode,indicating a 3.9-fold improvement in photocurrent density.Detailed physicochemical characterization and density functional theory calculations showed that the lattice distortion induced by Cs doping promoted the directional migration of BiVO_(4) bulk-phase holes to the CoFe_(2)O_(4) layer.Additionally,the coupled CoFe_(2)O_(4) can be used as a hole extraction layer to further enhance the interfacial migration of carriers.The synergistic effect of the two effectively promotes the directional migration of photogenerated carriers from the BiVO_(4) bulk phase to the active sites of the oxygen evolution reaction,thereby effectively inhibiting carrier recombination.This study revealed the positive effect of the dual-hole extraction strategy on solar energy conversion,thereby opening new avenues for the rational design of photoanodes.展开更多
With the advancement of modern science and technology, large scientific facilities are increasingly oriented toward demand and application, and can be used for basic research as well as serving multiple disciplines. D...With the advancement of modern science and technology, large scientific facilities are increasingly oriented toward demand and application, and can be used for basic research as well as serving multiple disciplines. Developing large scientific facilities and related analytical technologies enhances understanding of large scientific facilities and popularizes their application in research across multiple disciplines. The combination of light or neutron sources from large scientific facilities and advanced analytical technologies can be achieved for materials structure information, dynamics study of chemical reactions, high dissociation of biomolecules, 3D visualization of energy materials or biological samples, etc. We first introduce the progress of domestic large scientific facilities of synchrotron radiation(SR) and free electron lasers(FELs) with different wavelengths and neutron sources.We further discuss the comparison between Chinese and typical foreign facilities in X-ray radiation from X-ray tubes, synchrotrons, X-ray FELs, and neutron sources based on physical parameters of light and neutron sources. In addition, we focus on the technological progress and perspectives combined with advanced X-ray radiation and neutron sources of large scientific facilities in China, especially in the nanoscience fields of energy catalysis and biological science. We hope that this roadmap will provide references on technology and methods to experimental users, as well as prospects for future development of technologies based on large research infrastructure facilities. Comprehensive studies and guidelines for basic research to practical application in various disciplines can be made with the assistance of large scientific facilities.展开更多
As one of the most promising CO_(2)utilization techniques,electrochemical CO_(2)reduction has recently received considerable attention.Cu is a unique electrocatalyst that can convert CO_(2)to value-added multi-carbon ...As one of the most promising CO_(2)utilization techniques,electrochemical CO_(2)reduction has recently received considerable attention.Cu is a unique electrocatalyst that can convert CO_(2)to value-added multi-carbon chemicals.Nevertheless,Cu catalysts are always limited by the poor selectivity and stability.Here,we report that using copper-tetracyanoquinodimethane(CuTCNQ)derived Cu nanoparticles as efficient electrocatalysts for conversion of CO_(2)to ethylene characteristic with high selectivity and stability,showing 56%Faradaic efficiency(FE)to C2H4 at−1.3 V vs.reversible hydrogen electrode(RHE).Upon the electrochemical CO_(2)reduction,CuTCNQ slowly reconstructs to Cu nanoparticles with abundant grain boundaries and residual Cu+on the surface.Theoretical calculation and operando characterization disclose that both as-formed Cu nanoparticle grain boundaries and residual Cu+endow the catalyst with high selectivity toward ethylene.Furthermore,during the reconstruction of CuTCNQ to Cu nanoparticles,the grain boundaries Cu surface is slowly refreshed by continual addition of Cu atoms,thus inhibiting the surface passivation and guaranteeing the electrocatalytic stability.展开更多
Single site catalysts provide a unique platform for mimicking natural enzyme due to their tunable interaction between metal center and coordinated ligand.However,most works have focused on preparing structural and fun...Single site catalysts provide a unique platform for mimicking natural enzyme due to their tunable interaction between metal center and coordinated ligand.However,most works have focused on preparing structural and functional models of nature enzyme,with less reports also taking the local chemical environment,i.e.,functional/catalytic residues around the active site which is an essential feature of enzymes,into consideration.Herein,we report a Co-centered porphyrinic polymer containing the enzyme-mimic micro-environment,where the linker triazole over CoN4 site enables formation of hydrogen bond with the*COOH intermediate,thus promoting the electrocatalytic reduction of CO_(2).As-prepared catalyst achieves the CO_(2)-to-CO conversion of 5,788 h^(−1) turnover frequency value and near unit(~96%)faradaic efficiency at−0.61 V versus reversible hydrogen electrode.This strategy will bring new dimension of designing highly active single-site catalysts.展开更多
Purpose A new mobile grazing-incidence X-ray absorption fine spectroscopy(GIXAFS)endstation was developed at Beijing Synchrotron Radiation Facility(BSRF)to improve the function of general XAFS beamlines and extend the...Purpose A new mobile grazing-incidence X-ray absorption fine spectroscopy(GIXAFS)endstation was developed at Beijing Synchrotron Radiation Facility(BSRF)to improve the function of general XAFS beamlines and extend their capabilities to a wider user community.Methods We developed a facile GIXAFS endstation through modifying the regular XAFS in grazing-incidence geometry.Additionally,a soller slit,filter,photographic film and tiny lead sheets were assembled to improve the signal-to-noise ratio of XAFS data.Furtherly,combined with time-resolved quick scanning XAFS(QXAFS)techniques,the systems can perform in situ XAFS measurement to study materials under operando condition.Results The GIXAFS had been used to collect the Ga K-edge XAFS of InGaN thin film on sapphire substrate,which demonstrated that signal-to-noise ratio of XAFS data had been greatly improved through suppressing the effect of substrate diffractions.Moreover,the feasibility of GIXAFS-QXAFS combination was illustrated with in situ exploring the degradation of organic-inorganic perovskites under X-ray radiation.Conclusion A new mobile and facile GIXAFS endstation has been developed for thin films study.Based on the photographic film and lead sheets,the contamination of the XAFS from the matrix is minimized.Further combined with QXAFS techniques,the systems are used to reveal the X-ray-induced organic-inorganic perovskite thin films photodegrading process,which proved their successful application in the time-resolved measurements,extending the capabilities of general beamlines available to a wider user community.展开更多
文摘Elemental doping of BiVO_(4) crystal lattices effectively enhances carrier separation,thereby facilitating efficient photoelectrochemical water splitting.However,the positive effect of elementally induced lattice distortions on hole extraction has been neglected.Herein,the crystal lattice of BiVO_(4) is distorted by doping with an inexpensive Cs metal;then,CoFe_(2)O_(4) is used as an efficient hole-extraction layer to further modify the surface of the doped photoanode.Benefiting from the above design,the newly prepared CoFe_(2)O_(4)-Cs-BiVO_(4) photoanode achieved a photocurrent density of 5.66 mA cm^(–2) at 1.23 V vs.a reversible hydrogen electrode,indicating a 3.9-fold improvement in photocurrent density.Detailed physicochemical characterization and density functional theory calculations showed that the lattice distortion induced by Cs doping promoted the directional migration of BiVO_(4) bulk-phase holes to the CoFe_(2)O_(4) layer.Additionally,the coupled CoFe_(2)O_(4) can be used as a hole extraction layer to further enhance the interfacial migration of carriers.The synergistic effect of the two effectively promotes the directional migration of photogenerated carriers from the BiVO_(4) bulk phase to the active sites of the oxygen evolution reaction,thereby effectively inhibiting carrier recombination.This study revealed the positive effect of the dual-hole extraction strategy on solar energy conversion,thereby opening new avenues for the rational design of photoanodes.
基金supported by the National Basic Research Program of China (2022YFA1603701, 2021YFA1200900)the institutionalized scientific research platform relies on Beijing Synchrotron Radiation Facility of Chinese Academy of Sciences,the Strategic Priority Research Program of Chinese Academy of Sciences (XDB36000000)+2 种基金the National Natural Science Foundation of China (22027810, 82341044,22388101 and 22307028)the CAMS Innovation Fund for Medical Sciences(CIFMS 2019-I2M-5-018)the New Cornerstone Science Foundation。
文摘With the advancement of modern science and technology, large scientific facilities are increasingly oriented toward demand and application, and can be used for basic research as well as serving multiple disciplines. Developing large scientific facilities and related analytical technologies enhances understanding of large scientific facilities and popularizes their application in research across multiple disciplines. The combination of light or neutron sources from large scientific facilities and advanced analytical technologies can be achieved for materials structure information, dynamics study of chemical reactions, high dissociation of biomolecules, 3D visualization of energy materials or biological samples, etc. We first introduce the progress of domestic large scientific facilities of synchrotron radiation(SR) and free electron lasers(FELs) with different wavelengths and neutron sources.We further discuss the comparison between Chinese and typical foreign facilities in X-ray radiation from X-ray tubes, synchrotrons, X-ray FELs, and neutron sources based on physical parameters of light and neutron sources. In addition, we focus on the technological progress and perspectives combined with advanced X-ray radiation and neutron sources of large scientific facilities in China, especially in the nanoscience fields of energy catalysis and biological science. We hope that this roadmap will provide references on technology and methods to experimental users, as well as prospects for future development of technologies based on large research infrastructure facilities. Comprehensive studies and guidelines for basic research to practical application in various disciplines can be made with the assistance of large scientific facilities.
基金the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB36000000,Z.Y.T.)National Key Basic Research Program of China(No.2021YFA1200302,Z.Y.T.)+1 种基金National Natural Science Foundation of China(Nos.92056204,21890381,and 21721002,Z.Y.T.)of 1W1B and 4B9A beamline of Beijing Synchrotron Radiation Facility(BSRF).
文摘As one of the most promising CO_(2)utilization techniques,electrochemical CO_(2)reduction has recently received considerable attention.Cu is a unique electrocatalyst that can convert CO_(2)to value-added multi-carbon chemicals.Nevertheless,Cu catalysts are always limited by the poor selectivity and stability.Here,we report that using copper-tetracyanoquinodimethane(CuTCNQ)derived Cu nanoparticles as efficient electrocatalysts for conversion of CO_(2)to ethylene characteristic with high selectivity and stability,showing 56%Faradaic efficiency(FE)to C2H4 at−1.3 V vs.reversible hydrogen electrode(RHE).Upon the electrochemical CO_(2)reduction,CuTCNQ slowly reconstructs to Cu nanoparticles with abundant grain boundaries and residual Cu+on the surface.Theoretical calculation and operando characterization disclose that both as-formed Cu nanoparticle grain boundaries and residual Cu+endow the catalyst with high selectivity toward ethylene.Furthermore,during the reconstruction of CuTCNQ to Cu nanoparticles,the grain boundaries Cu surface is slowly refreshed by continual addition of Cu atoms,thus inhibiting the surface passivation and guaranteeing the electrocatalytic stability.
基金the National Science Fund for Distinguished Young Scholars(No.51825202)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB36000000)+2 种基金the National Key Basic Research Program of China(No.2016YFA0200700)the National Natural Science Foundation of China(Nos.21775032,92056204,21890381,and 21721002)Frontier Science Key Project of Chinese Academy of Sciences(No.QYZDJ-SSW-SLH038).
文摘Single site catalysts provide a unique platform for mimicking natural enzyme due to their tunable interaction between metal center and coordinated ligand.However,most works have focused on preparing structural and functional models of nature enzyme,with less reports also taking the local chemical environment,i.e.,functional/catalytic residues around the active site which is an essential feature of enzymes,into consideration.Herein,we report a Co-centered porphyrinic polymer containing the enzyme-mimic micro-environment,where the linker triazole over CoN4 site enables formation of hydrogen bond with the*COOH intermediate,thus promoting the electrocatalytic reduction of CO_(2).As-prepared catalyst achieves the CO_(2)-to-CO conversion of 5,788 h^(−1) turnover frequency value and near unit(~96%)faradaic efficiency at−0.61 V versus reversible hydrogen electrode.This strategy will bring new dimension of designing highly active single-site catalysts.
基金support by the National Key Research and Development Program of China(Grant No.2017YFA0403400)the National Natural Science Foundation of China(NSFC)(U1932201,U2032202)
文摘Purpose A new mobile grazing-incidence X-ray absorption fine spectroscopy(GIXAFS)endstation was developed at Beijing Synchrotron Radiation Facility(BSRF)to improve the function of general XAFS beamlines and extend their capabilities to a wider user community.Methods We developed a facile GIXAFS endstation through modifying the regular XAFS in grazing-incidence geometry.Additionally,a soller slit,filter,photographic film and tiny lead sheets were assembled to improve the signal-to-noise ratio of XAFS data.Furtherly,combined with time-resolved quick scanning XAFS(QXAFS)techniques,the systems can perform in situ XAFS measurement to study materials under operando condition.Results The GIXAFS had been used to collect the Ga K-edge XAFS of InGaN thin film on sapphire substrate,which demonstrated that signal-to-noise ratio of XAFS data had been greatly improved through suppressing the effect of substrate diffractions.Moreover,the feasibility of GIXAFS-QXAFS combination was illustrated with in situ exploring the degradation of organic-inorganic perovskites under X-ray radiation.Conclusion A new mobile and facile GIXAFS endstation has been developed for thin films study.Based on the photographic film and lead sheets,the contamination of the XAFS from the matrix is minimized.Further combined with QXAFS techniques,the systems are used to reveal the X-ray-induced organic-inorganic perovskite thin films photodegrading process,which proved their successful application in the time-resolved measurements,extending the capabilities of general beamlines available to a wider user community.
