The high unoccupied d band energy of Ni_(3)N basically results in weak orbital coupling with water molecule,consequently leading to slow water dissociation kinetics.Herein,we demonstrate Cr doping can downshift the un...The high unoccupied d band energy of Ni_(3)N basically results in weak orbital coupling with water molecule,consequently leading to slow water dissociation kinetics.Herein,we demonstrate Cr doping can downshift the unoccupied d orbitals and strengthen the interfacial orbital coupling to boost the water dissociation kinetics.The prepared Cr-Ni_(3)N/Ni displays an impressive overpotential of 37 mV at 10 mA·cmgeo-2,close to the benchmark Pt/C in 1.0 M KOH solution.Refined structural analysis reveals the Cr dopant exists as the Cr-N_(6)states and the average d band energy of Ni_(3)N is also lowered.Density functional theory calculation further confirms the downshifted d band energy can strengthen the orbital coupling between the unpaired electrons in O 2p and the unoccupied state of Ni 3d,which thus facilitates the water adsorption and dissociation.The work provides a new concept to achieve on-demand functions for hydrogen evolution catalysis and beyond,by regulating the interfacial orbital coupling.展开更多
基金The work was supported by the National Natural Science Foundation of China(Nos.21771169 and 11722543)the National Key Research and Development Program of China(No.2017YFA0206703)+1 种基金Anhui Provincial Natural Science Foundation(No.BJ2060190077)Collaborative Innovation Program of Hefei Science Center,CAS,and the Fundamental Research Funds for the Central Universities(Nos.WK2060190074,WK2060190081,WK2310000066,and WK2060000015).
文摘The high unoccupied d band energy of Ni_(3)N basically results in weak orbital coupling with water molecule,consequently leading to slow water dissociation kinetics.Herein,we demonstrate Cr doping can downshift the unoccupied d orbitals and strengthen the interfacial orbital coupling to boost the water dissociation kinetics.The prepared Cr-Ni_(3)N/Ni displays an impressive overpotential of 37 mV at 10 mA·cmgeo-2,close to the benchmark Pt/C in 1.0 M KOH solution.Refined structural analysis reveals the Cr dopant exists as the Cr-N_(6)states and the average d band energy of Ni_(3)N is also lowered.Density functional theory calculation further confirms the downshifted d band energy can strengthen the orbital coupling between the unpaired electrons in O 2p and the unoccupied state of Ni 3d,which thus facilitates the water adsorption and dissociation.The work provides a new concept to achieve on-demand functions for hydrogen evolution catalysis and beyond,by regulating the interfacial orbital coupling.
