Cobalt‐based materials have been considered as promising candidates to electrocatalyze water oxidation.However,the structure‐performance correlation remains largely elusive,due to the com‐plex material structures a...Cobalt‐based materials have been considered as promising candidates to electrocatalyze water oxidation.However,the structure‐performance correlation remains largely elusive,due to the com‐plex material structures and diverse performance‐influencing factors in those Co‐based catalysts.In this work,we designed two cobalt phosphates with distinct Co symmetry to explore the effect of coordination symmetry on electrocatalytic water oxidation.The two analogues have similar mor‐phology,Co valence and 6‐coordinated Co octahedron,but with different coordination symmetry.In contrast to symmetric Co_(3)(PO_(4))2·8H_(2)O,asymmetric NH_(4)CoPO_(4)·H_(2)O exhibited enhanced electrocata‐lytic water oxidation activity in a neutral aqueous solution.It is proven that,by experimental and theoretical studies,the asymmetric Co coordination sites can facilitate the surface reconstruction under anodic polarization to boost the electrocatalysis.Based on this contrastive platform with distinct symmetry differences,the preferred configuration in cobalt‐oxygen octahedrons for water oxidation has been straightforwardly assigned.展开更多
The electronic structure and possible electronic orders in monolayer NbF4 are investigated by density functional theory and functional renormalization group.Because of the niobium-centered octahedra,the energy band ne...The electronic structure and possible electronic orders in monolayer NbF4 are investigated by density functional theory and functional renormalization group.Because of the niobium-centered octahedra,the energy band near the Fermi level is found to derive from the 4 dxyorbital,well separated from the other bands.Local Coulomb interaction drives the undoped system into an antiferromagnetic insulator.Upon suitable electron/hole doping,the system is found to develop dx2à-y2 wave superconductivity with sizable transition temperature.Therefore,the monolayer NbF4 may be an exciting 4d1 analogue of cuprates,providing a new two-dimensional platform for high-Tc superconductivity.展开更多
文摘Cobalt‐based materials have been considered as promising candidates to electrocatalyze water oxidation.However,the structure‐performance correlation remains largely elusive,due to the com‐plex material structures and diverse performance‐influencing factors in those Co‐based catalysts.In this work,we designed two cobalt phosphates with distinct Co symmetry to explore the effect of coordination symmetry on electrocatalytic water oxidation.The two analogues have similar mor‐phology,Co valence and 6‐coordinated Co octahedron,but with different coordination symmetry.In contrast to symmetric Co_(3)(PO_(4))2·8H_(2)O,asymmetric NH_(4)CoPO_(4)·H_(2)O exhibited enhanced electrocata‐lytic water oxidation activity in a neutral aqueous solution.It is proven that,by experimental and theoretical studies,the asymmetric Co coordination sites can facilitate the surface reconstruction under anodic polarization to boost the electrocatalysis.Based on this contrastive platform with distinct symmetry differences,the preferred configuration in cobalt‐oxygen octahedrons for water oxidation has been straightforwardly assigned.
基金the National Key Research and Development Program of China(2016YFA0300401)the National Natural Science Foundation of China(11604303,11604168 and 11574134)+1 种基金the Texas Center for Superconductivity at the University of Houston and the Robert A.Welch Foundation(E-1146)the support from China Scholarship Council(201909440001)。
文摘The electronic structure and possible electronic orders in monolayer NbF4 are investigated by density functional theory and functional renormalization group.Because of the niobium-centered octahedra,the energy band near the Fermi level is found to derive from the 4 dxyorbital,well separated from the other bands.Local Coulomb interaction drives the undoped system into an antiferromagnetic insulator.Upon suitable electron/hole doping,the system is found to develop dx2à-y2 wave superconductivity with sizable transition temperature.Therefore,the monolayer NbF4 may be an exciting 4d1 analogue of cuprates,providing a new two-dimensional platform for high-Tc superconductivity.
