The vibrational motions are usually neglected when calculating(e,2e) triple differential cross sections(TDCSs) of molecules. Here, multi-center distorted-wave method(MCDW) has been modified by including molecular vibr...The vibrational motions are usually neglected when calculating(e,2e) triple differential cross sections(TDCSs) of molecules. Here, multi-center distorted-wave method(MCDW) has been modified by including molecular vibrations. This vibrational MCDW method is employed to calculate the TDCSs of 1b3gorbital of ethylene at low(100 eV) and medium(250 eV) incident electron energies in coplanar asymmetric kinematic condition. The results show that molecular vibrations significantly influence the angular distributions of the TDCSs, especially in the binary region along momentum transfer near the Bethe ridge.展开更多
Objective: The human cluster of differentiation(CD)300A, a type-I transmembrane protein with immunoreceptor tyrosine-based inhibitory motifs, was investigated as a potential immune checkpoint for human natural killer(...Objective: The human cluster of differentiation(CD)300A, a type-I transmembrane protein with immunoreceptor tyrosine-based inhibitory motifs, was investigated as a potential immune checkpoint for human natural killer(NK) cells targeting hematologic malignancies(HMs).Methods: We implemented a stimulation system involving the CD300A ligand, phosphatidylserine(PS), exposed to the outer surface of malignant cells. Additionally, we utilized CD300A overexpression, a CD300A blocking system, and a xenotransplantation model to evaluate the impact of CD300A on NK cell efficacy against HMs in in vitro and in vivo settings. Furthermore, we explored the association between CD300A and HM progression in patients.Results: Our findings indicated that PS hampers the function of NK cells. Increased CD300A expression inhibited HM lysis by NK cells. CD300A overexpression shortened the survival of HM-xenografted mice by impairing transplanted NK cells. Blocking PS–CD300A signals with antibodies significantly amplified the expression of lysis function-related proteins and effector cytokines in NK cells, thereby augmenting the ability to lyse HMs. Clinically, heightened CD300A expression correlated with shorter survival and an “exhausted” phenotype of intratumoral NK cells in patients with HMs or solid tumors.Conclusions: These results propose CD300A as a potential target for invigorating NK cell-based treatments against HMs.展开更多
Electron-impact excitation integral cross sections play an important role in understanding the energy transfer processes in many applied physics. Practical applications require integral cross sections in a wide collis...Electron-impact excitation integral cross sections play an important role in understanding the energy transfer processes in many applied physics. Practical applications require integral cross sections in a wide collision energy range from the excitation threshold to several ke V. The recently developed BE-scaling method is able to meet the demands of integral cross sections for dipole-allowed transitions while the prerequisite relies on the accurate generalized oscillator strengths. Fast electron and x-ray scatterings are the conventional experimental techniques to approach the generalized oscillator strengths,and the joint study by both methods can provide credible cross-checks. The validated generalized oscillator strengths can then be used to extrapolate optical oscillator strengths by fitting the data with the Lassettre formula. The fitted curve also enables the integration of generalized oscillator strengths over the whole momentum transfer region to obtain the BE-scaled integral excitation cross sections. Here, experimental measurements by both fast electron and x-ray scattering of argon and carbon dioxide are reviewed. The integral cross sections for some low-lying states are derived from the cross-checked generalized oscillator strengths for the first time. The integral cross sections presented in this paper are openly available at https://doi.org/10.11922/sciencedb.01466.展开更多
Dielectronic recombination(DR)is one of the dominant electron-ion recombination mechanisms for most highly charged ions(HCIs)in cosmic plasmas,and thus,it determines the charge state distribution and ionization balanc...Dielectronic recombination(DR)is one of the dominant electron-ion recombination mechanisms for most highly charged ions(HCIs)in cosmic plasmas,and thus,it determines the charge state distribution and ionization balance therein.To reliably interpret spectra from cosmic sources and model the astrophysical plasmas,precise DR rate coefficients are required to build up an accurate understanding of the ionization balance of the sources.The main cooler storage ring(CSRm)and the experimental cooler storage ring(CSRe)at the Heavy-Ion Research Facility in Lanzhou(HIRFL)are both equipped with electron cooling devices,which provide an excellent experimental platform for electron-ion collision studies for HCIs.Here,the status of the DR experiments at the HIRFL-CSR is outlined,and the DR measurements with Na-like Kr25^(+)ions at the CSRm and CSRe are taken as examples.In addition,the plasma recombination rate coefficients for Ar12^(+),14^(+),Ca14^(+),16^(+),17^(+),Ni19^(+),and Kr25^(+)ions obtained at the HIRFL-CSR are provided.All the data presented in this paper are openly available at https://doi.org/10.57760/sciencedb.j00113.00092.展开更多
The oscillator strengths of the valence-shell excitations of C_(2)H_(2) are extremely important for testing theoretical models and studying interstellar gases.In this study,the high-resolution inelastic x-ray scatteri...The oscillator strengths of the valence-shell excitations of C_(2)H_(2) are extremely important for testing theoretical models and studying interstellar gases.In this study,the high-resolution inelastic x-ray scattering(IXS)method is adopted to determine the generalized oscillator strengths(GOSs)of the valence-shell excitations of C_(2)H_(2) at a photon energy of10 ke V.The GOSs are extrapolated to their zero limit to obtain the corresponding optical oscillator strengths(OOSs).Through taking a completely different experimental method of the IXS,the present results offer the high energy limit for electron collision to satisfy the first Born approximation(FBA)and cross-check the previous experimental and theoretical results independently.The comparisons indicate that an electron collision energy of 1500 e V is not enough for C_(2)H_(2) to satisfy the FBA for the large squared momentum transfer,and the line saturation effect limits the accuracy of the OOSs measured by the photoabsorption method.展开更多
As a prototypical half-metallic ferromagnet,La_(0.67)Sr_(0.33)MnO_(3)(LSMO)has been extensively studied due to its versatile physical properties and great potential in spintronic applications.However,the weak perpendi...As a prototypical half-metallic ferromagnet,La_(0.67)Sr_(0.33)MnO_(3)(LSMO)has been extensively studied due to its versatile physical properties and great potential in spintronic applications.However,the weak perpendicular magnetic anisotropy(PMA)limits the controllability and detection of magnetism in LSMO,thus hindering the realization of oxide-based spintronic devices with low energy consumption and high integration level.Motivated by this challenge,we develop an experimental approach to enhance the PMA of LSMO epitaxial films.By cooperatively introducing 4d Ru doping and a moderate compressive strain,the maximum uniaxial magnetic anisotropy in Ru-doped LSMO can reach 3.0×10^(5)J/m^(3)at 10 K.Furthermore,we find a significant anisotropic magnetoresistance effect in these Ru-doped LSMO films,which is dominated by the strong PMA.Our findings offer an effective pathway to harness and detect the orientations of magnetic moments in LSMO films,thus promoting the feasibility of oxide-based spintronic devices,such as spin valves and magnetic tunnel junctions.展开更多
Two-dimensional systems that simultaneously harbor superconductivity and nontrivial band topology may serve as appealing platforms for realizing topological superconductivity with promising applications in fault-toler...Two-dimensional systems that simultaneously harbor superconductivity and nontrivial band topology may serve as appealing platforms for realizing topological superconductivity with promising applications in fault-tolerant quantum computing.Here,based on first-principles calculations,we show that monolayered Co N and Co P with the isovalent Fe Se-like structure are stable in freestanding form,even though their known bulk phases have no resemblance to layering.The two systems are further revealed to display intrinsic band inversions due to crystal field splitting,and such orderings are preserved with the inclusion of spin-orbit coupling(SOC),which otherwise is able to open a curved band gap,yielding a non-zero Z2 topological invariant in each case.Such a mechanism of topologicalization is distinctly contrasted with that identified recently for the closely related monolayers of CoX(X=As,Sb,Bi),where the SOC plays an indispensable role in causing a nontrivial band inversion.Next,we demonstrate that,by applying equi-biaxial tensile strain,the electron-phonon coupling strength in monolayered CoN can be significantly enhanced,yielding a superconducting transition temperature(Tc)up to 7-12 K for the Coulomb pseudopotential ofμ*=0.2-0.1,while the CoP monolayer shows very low Tc even under pronounced strain.Their different superconducting behaviors can be attributed to different variations in lattice softening and electronic density of states around the Fermi level upon pressuring.Our central findings enrich the understanding of different mechanisms of band inversions and topologicalization and offer platforms for achieving the coexistence of superconductivity and nontrivial band topology based on two-dimensional systems.展开更多
Selective photooxidation of amines to biologically important imines is in great demand for industrial applications.The conversion efficiency and selectivity of the process are strongly dependent on the activation of p...Selective photooxidation of amines to biologically important imines is in great demand for industrial applications.The conversion efficiency and selectivity of the process are strongly dependent on the activation of photocatalytic molecular oxygen(O_(2))into reactive oxygen species.Here,we propose the construction of rich interfaces to boost photocatalytic O_(2) activation by facilitating the transfer of photocarriers.Taking Bi_(3)O_(4)Br/Bi_(2)O_(3) heterojunctions as an example,rich interfaces facilitate electron transfer to adsorbed O_(2) for superoxide(O_(2)⋅^(-))generation,thus achieving≥98%conversion efficiency and selectivity for benzylamine and benzylamine derivatives.This study offers a valid method to design advanced photocatalysts for selective oxidation reactions.展开更多
CO_(2)photoreduction to high-valued CH_(4)is highly attractive,whereas the CH_(4)selectivity and activity,especially under atmospheric CO_(2),is still unsatisfying.Here,we design spatially-separated redox sites on two...CO_(2)photoreduction to high-valued CH_(4)is highly attractive,whereas the CH_(4)selectivity and activity,especially under atmospheric CO_(2),is still unsatisfying.Here,we design spatially-separated redox sites on two-dimensional heterostructured nanosheets with loaded metal oxides,thus achieving high reactivity and selectivity of photocatalytic atmospheric CO_(2)reduction to CH_(4).Taking the synthetic In_(2)O_(3)/In_(2)S_(3)nanosheets with loaded PdO quantum dots as a prototype,quasi in-situ X-ray photoelectron spectra reveal the Pd sites accumulate photogenerated holes for dissociating H_(2)O and the In sites accept photoexcited electrons to activate CO_(2).Moreover,the Pd-OD bond is confirmed by in-situ Fourier-transform infrared spectra during the D2O labeling experiment,indicating the PdO quantum dots participate in H_(2)O oxidation to supply hydrogen species for CO_(2)methanation.As a result,in a simulated air atmosphere,the PdO-In_(2)O_(3)/In_(2)S_(3)nanosheets enable favorable atmospheric CO_(2)-to CH_(4)photoreduction with nearly 100%selectivity and ultralong stability of 240 h as well as CO_(2)conversion of 48.2%.This study opens an approach towards designing photocatalysts with spatially-separated redox sites to achieve efficient oxidation and reduction of CO_(2)photocatalysis to CH_(4).展开更多
High-rate CO_(2)-to-CH_(4)photoreduction with high selectivity is highly attractive,which is a win-win strategy for mitigating the greenhouse effect and the energy crisis.However,the poor photocatalytic activity and l...High-rate CO_(2)-to-CH_(4)photoreduction with high selectivity is highly attractive,which is a win-win strategy for mitigating the greenhouse effect and the energy crisis.However,the poor photocatalytic activity and low product selectivity hinder the practical application.To precisely tailor the product selectivity and realize high-rate CO_(2)photoreduction,we design atomically precise Pd species supported on In_(2)O_(3)nanosheets.Taking the synthetic 1.30Pd/In_(2)O_(3)nanosheets as an example,the aberration-correction high-angle annular dark-field scanning transmission electron microscopy image displayed the Pd species atomically dispersed on the In_(2)O_(3)nanosheets.Raman spectra and X-ray photoelectron spectra established that the strong interaction between the Pd species and the In_(2)O_(3)substrate drove electron transfer from In to Pd species,resulting in electron-enriched Pd sites for CO_(2)activation.Synchrotronradiation photoemission spectroscopy demonstrated that the Pd species can tailor the conduction band edge of In_(2)O_(3)nanosheets to match the CO_(2)-to-CH_(4)pathway,instead of the CO_(2)-to-CO pathway,which theoretically accounts for the high CH_(4)selectivity.Moreover,in situ X-ray photoelectron spectroscopy unveiled that the catalytically active sites had a change from In species to Pd species over the 1.30Pd/In_(2)O_(3)nanosheets.In situ FTIR and EPR spectra reveal the atomically precise Pd species with rich electrons prefer to adsorb the electrophilic protons for accelerating the*COOH intermediates hydrogenation into CH_(4).Consequently,the 1.30Pd/In_(2)O_(3)nanosheets reached CO_(2)-to-CH_(4)photoconversion with 100%selectivity and 81.2μmol g^(−1)h^(−1)productivity.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12004370 and 12127804)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB34020000)。
文摘The vibrational motions are usually neglected when calculating(e,2e) triple differential cross sections(TDCSs) of molecules. Here, multi-center distorted-wave method(MCDW) has been modified by including molecular vibrations. This vibrational MCDW method is employed to calculate the TDCSs of 1b3gorbital of ethylene at low(100 eV) and medium(250 eV) incident electron energies in coplanar asymmetric kinematic condition. The results show that molecular vibrations significantly influence the angular distributions of the TDCSs, especially in the binary region along momentum transfer near the Bethe ridge.
基金supported by the National Key R&D Program of China (2019YFA0508502/3 and 2021YFC2300604)the Natural Science Foundation of China (Reference numbers 82388201, 82241216, and 32270963)+1 种基金the Research Funds of Center for Advanced Interdisciplinary Science and Biomedicine of IHM (QYZD20220008)the Anhui Key Research and Development Plan (Reference number 2023z04020011)。
文摘Objective: The human cluster of differentiation(CD)300A, a type-I transmembrane protein with immunoreceptor tyrosine-based inhibitory motifs, was investigated as a potential immune checkpoint for human natural killer(NK) cells targeting hematologic malignancies(HMs).Methods: We implemented a stimulation system involving the CD300A ligand, phosphatidylserine(PS), exposed to the outer surface of malignant cells. Additionally, we utilized CD300A overexpression, a CD300A blocking system, and a xenotransplantation model to evaluate the impact of CD300A on NK cell efficacy against HMs in in vitro and in vivo settings. Furthermore, we explored the association between CD300A and HM progression in patients.Results: Our findings indicated that PS hampers the function of NK cells. Increased CD300A expression inhibited HM lysis by NK cells. CD300A overexpression shortened the survival of HM-xenografted mice by impairing transplanted NK cells. Blocking PS–CD300A signals with antibodies significantly amplified the expression of lysis function-related proteins and effector cytokines in NK cells, thereby augmenting the ability to lyse HMs. Clinically, heightened CD300A expression correlated with shorter survival and an “exhausted” phenotype of intratumoral NK cells in patients with HMs or solid tumors.Conclusions: These results propose CD300A as a potential target for invigorating NK cell-based treatments against HMs.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0402300)the National Natural Science Foundation of China(Grant Nos.U1932207 and 12104437)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB34000000)The financial support from the Heavy Ion Research Facility in Lanzhou(HIRFL)。
文摘Electron-impact excitation integral cross sections play an important role in understanding the energy transfer processes in many applied physics. Practical applications require integral cross sections in a wide collision energy range from the excitation threshold to several ke V. The recently developed BE-scaling method is able to meet the demands of integral cross sections for dipole-allowed transitions while the prerequisite relies on the accurate generalized oscillator strengths. Fast electron and x-ray scatterings are the conventional experimental techniques to approach the generalized oscillator strengths,and the joint study by both methods can provide credible cross-checks. The validated generalized oscillator strengths can then be used to extrapolate optical oscillator strengths by fitting the data with the Lassettre formula. The fitted curve also enables the integration of generalized oscillator strengths over the whole momentum transfer region to obtain the BE-scaled integral excitation cross sections. Here, experimental measurements by both fast electron and x-ray scattering of argon and carbon dioxide are reviewed. The integral cross sections for some low-lying states are derived from the cross-checked generalized oscillator strengths for the first time. The integral cross sections presented in this paper are openly available at https://doi.org/10.11922/sciencedb.01466.
基金supported by the National Natural Science Foundation of China (Grant Nos. U1932207, 11904371, and 12104437)the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB34020000)
文摘Dielectronic recombination(DR)is one of the dominant electron-ion recombination mechanisms for most highly charged ions(HCIs)in cosmic plasmas,and thus,it determines the charge state distribution and ionization balance therein.To reliably interpret spectra from cosmic sources and model the astrophysical plasmas,precise DR rate coefficients are required to build up an accurate understanding of the ionization balance of the sources.The main cooler storage ring(CSRm)and the experimental cooler storage ring(CSRe)at the Heavy-Ion Research Facility in Lanzhou(HIRFL)are both equipped with electron cooling devices,which provide an excellent experimental platform for electron-ion collision studies for HCIs.Here,the status of the DR experiments at the HIRFL-CSR is outlined,and the DR measurements with Na-like Kr25^(+)ions at the CSRm and CSRe are taken as examples.In addition,the plasma recombination rate coefficients for Ar12^(+),14^(+),Ca14^(+),16^(+),17^(+),Ni19^(+),and Kr25^(+)ions obtained at the HIRFL-CSR are provided.All the data presented in this paper are openly available at https://doi.org/10.57760/sciencedb.j00113.00092.
基金Project supported by the Strategic Priority Research Program of the Chinese Academy of Science(Grant No.XDB34000000)the National Natural Science Foundation of China(Grant Nos.U1932207 and 12104437)+3 种基金the National Key Research and Development Program of China(Grant No.2017YFA0402300)The support from the Heavy Ion Research Facility in Lanzhou(HIRFL)the BL12XU of SPring-8 with the approval of Japan Synchrotron Radiation Research Institute(Proposal No.2019A4275)“National”Synchrotron Radiation Research Center,Taiwan,China(Proposal No.2019-2-089-1)。
文摘The oscillator strengths of the valence-shell excitations of C_(2)H_(2) are extremely important for testing theoretical models and studying interstellar gases.In this study,the high-resolution inelastic x-ray scattering(IXS)method is adopted to determine the generalized oscillator strengths(GOSs)of the valence-shell excitations of C_(2)H_(2) at a photon energy of10 ke V.The GOSs are extrapolated to their zero limit to obtain the corresponding optical oscillator strengths(OOSs).Through taking a completely different experimental method of the IXS,the present results offer the high energy limit for electron collision to satisfy the first Born approximation(FBA)and cross-check the previous experimental and theoretical results independently.The comparisons indicate that an electron collision energy of 1500 e V is not enough for C_(2)H_(2) to satisfy the FBA for the large squared momentum transfer,and the line saturation effect limits the accuracy of the OOSs measured by the photoabsorption method.
基金supported by the National Basic Research Program of China(Grant No.2020YFA0309100)the National Natural Science Foundation of China(Grant Nos.12074365,U2032218,and 11974326)+1 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.WK9990000102 and WK2030000035)the China Postdoctoral Science Foundation(Gaint No.2022M713060)。
文摘As a prototypical half-metallic ferromagnet,La_(0.67)Sr_(0.33)MnO_(3)(LSMO)has been extensively studied due to its versatile physical properties and great potential in spintronic applications.However,the weak perpendicular magnetic anisotropy(PMA)limits the controllability and detection of magnetism in LSMO,thus hindering the realization of oxide-based spintronic devices with low energy consumption and high integration level.Motivated by this challenge,we develop an experimental approach to enhance the PMA of LSMO epitaxial films.By cooperatively introducing 4d Ru doping and a moderate compressive strain,the maximum uniaxial magnetic anisotropy in Ru-doped LSMO can reach 3.0×10^(5)J/m^(3)at 10 K.Furthermore,we find a significant anisotropic magnetoresistance effect in these Ru-doped LSMO films,which is dominated by the strong PMA.Our findings offer an effective pathway to harness and detect the orientations of magnetic moments in LSMO films,thus promoting the feasibility of oxide-based spintronic devices,such as spin valves and magnetic tunnel junctions.
基金supported by the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302800)the National Natural Science Foundation of China(Grant Nos.11974323,and 12374458)+2 种基金the Anhui Initiative in Quantum Information Technologies(Grant No.AHY170000)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB0510200)the Anhui Provincial Key Research and Development Project(Grant No.2023z04020008)。
文摘Two-dimensional systems that simultaneously harbor superconductivity and nontrivial band topology may serve as appealing platforms for realizing topological superconductivity with promising applications in fault-tolerant quantum computing.Here,based on first-principles calculations,we show that monolayered Co N and Co P with the isovalent Fe Se-like structure are stable in freestanding form,even though their known bulk phases have no resemblance to layering.The two systems are further revealed to display intrinsic band inversions due to crystal field splitting,and such orderings are preserved with the inclusion of spin-orbit coupling(SOC),which otherwise is able to open a curved band gap,yielding a non-zero Z2 topological invariant in each case.Such a mechanism of topologicalization is distinctly contrasted with that identified recently for the closely related monolayers of CoX(X=As,Sb,Bi),where the SOC plays an indispensable role in causing a nontrivial band inversion.Next,we demonstrate that,by applying equi-biaxial tensile strain,the electron-phonon coupling strength in monolayered CoN can be significantly enhanced,yielding a superconducting transition temperature(Tc)up to 7-12 K for the Coulomb pseudopotential ofμ*=0.2-0.1,while the CoP monolayer shows very low Tc even under pronounced strain.Their different superconducting behaviors can be attributed to different variations in lattice softening and electronic density of states around the Fermi level upon pressuring.Our central findings enrich the understanding of different mechanisms of band inversions and topologicalization and offer platforms for achieving the coexistence of superconductivity and nontrivial band topology based on two-dimensional systems.
基金This work was supported by the National Key R&D Program of China(2022YFA1502903)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB36000000)+3 种基金the National Natural Science Foundation of China(92163105,T2122004,21890754,U2032212,U2032160)the Youth Innovation Promotion Association of CAS(Y2021123)the University Synergy Innovation Program of Anhui Province(GXXT-2020-005)the Fundamental Research Funds for the Central Universities(WK2060000039,WK2060000035).We gratefully acknowledge the supercomputing system in the Supercomputing Center of University of Science and Technology of China.
文摘Selective photooxidation of amines to biologically important imines is in great demand for industrial applications.The conversion efficiency and selectivity of the process are strongly dependent on the activation of photocatalytic molecular oxygen(O_(2))into reactive oxygen species.Here,we propose the construction of rich interfaces to boost photocatalytic O_(2) activation by facilitating the transfer of photocarriers.Taking Bi_(3)O_(4)Br/Bi_(2)O_(3) heterojunctions as an example,rich interfaces facilitate electron transfer to adsorbed O_(2) for superoxide(O_(2)⋅^(-))generation,thus achieving≥98%conversion efficiency and selectivity for benzylamine and benzylamine derivatives.This study offers a valid method to design advanced photocatalysts for selective oxidation reactions.
基金supported by the National Key Research and Development Program of China(2022YFA1502904,2019YFA0210004,2021YFA1501502)the National Natural Science Foundation of China(22125503,21975242,U2032212,21890754,22002148)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDB36000000)the Youth Innovation Promotion Association of Chinese Academy of Sciences(CX2340007003)the University Synergy Innovation Program of Anhui Province(GXXT-2020-001)
文摘CO_(2)photoreduction to high-valued CH_(4)is highly attractive,whereas the CH_(4)selectivity and activity,especially under atmospheric CO_(2),is still unsatisfying.Here,we design spatially-separated redox sites on two-dimensional heterostructured nanosheets with loaded metal oxides,thus achieving high reactivity and selectivity of photocatalytic atmospheric CO_(2)reduction to CH_(4).Taking the synthetic In_(2)O_(3)/In_(2)S_(3)nanosheets with loaded PdO quantum dots as a prototype,quasi in-situ X-ray photoelectron spectra reveal the Pd sites accumulate photogenerated holes for dissociating H_(2)O and the In sites accept photoexcited electrons to activate CO_(2).Moreover,the Pd-OD bond is confirmed by in-situ Fourier-transform infrared spectra during the D2O labeling experiment,indicating the PdO quantum dots participate in H_(2)O oxidation to supply hydrogen species for CO_(2)methanation.As a result,in a simulated air atmosphere,the PdO-In_(2)O_(3)/In_(2)S_(3)nanosheets enable favorable atmospheric CO_(2)-to CH_(4)photoreduction with nearly 100%selectivity and ultralong stability of 240 h as well as CO_(2)conversion of 48.2%.This study opens an approach towards designing photocatalysts with spatially-separated redox sites to achieve efficient oxidation and reduction of CO_(2)photocatalysis to CH_(4).
基金the National Key R&D Program of China(2022YFA1502904,2019YFA0210004,2021YFA1501502)National Natural Science Foundation of China(22125503,21975242,U2032212,21890754)+1 种基金Youth Innovation Promotion Association of CAS(CX2340007003)Technical Talent Promotion Plan(TS2021002).
文摘High-rate CO_(2)-to-CH_(4)photoreduction with high selectivity is highly attractive,which is a win-win strategy for mitigating the greenhouse effect and the energy crisis.However,the poor photocatalytic activity and low product selectivity hinder the practical application.To precisely tailor the product selectivity and realize high-rate CO_(2)photoreduction,we design atomically precise Pd species supported on In_(2)O_(3)nanosheets.Taking the synthetic 1.30Pd/In_(2)O_(3)nanosheets as an example,the aberration-correction high-angle annular dark-field scanning transmission electron microscopy image displayed the Pd species atomically dispersed on the In_(2)O_(3)nanosheets.Raman spectra and X-ray photoelectron spectra established that the strong interaction between the Pd species and the In_(2)O_(3)substrate drove electron transfer from In to Pd species,resulting in electron-enriched Pd sites for CO_(2)activation.Synchrotronradiation photoemission spectroscopy demonstrated that the Pd species can tailor the conduction band edge of In_(2)O_(3)nanosheets to match the CO_(2)-to-CH_(4)pathway,instead of the CO_(2)-to-CO pathway,which theoretically accounts for the high CH_(4)selectivity.Moreover,in situ X-ray photoelectron spectroscopy unveiled that the catalytically active sites had a change from In species to Pd species over the 1.30Pd/In_(2)O_(3)nanosheets.In situ FTIR and EPR spectra reveal the atomically precise Pd species with rich electrons prefer to adsorb the electrophilic protons for accelerating the*COOH intermediates hydrogenation into CH_(4).Consequently,the 1.30Pd/In_(2)O_(3)nanosheets reached CO_(2)-to-CH_(4)photoconversion with 100%selectivity and 81.2μmol g^(−1)h^(−1)productivity.