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The high unoccupied d band energy of Ni3N 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-Ni3N/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-N6 states and the average d band energy of Ni3N 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.