Engineering VN/Co5.47N Nanostructures with Interfacial Electronic and Atomic Reorganization for Oxygen Reduction and Zn-Air Batteries

Interfacial electronic and atomic structural reorganization in heterojunction hybrids will unlock great potential for achieving efficient catalysis. Herein, VN/Co5.47N nanopolyhedrons were first prepared by ammonization of functional ZIF-67 with vanadate and further employed as model catalysts to highlight the interfacial electronic and atomic synergistic effects on the oxygen reduction reaction (ORR). X-ray photoelectron spectroscopy confirms the charge transfer from Co5.47N to VN, which can further regulate the intrinsic electronic structure and accelerate the ORR catalytic kinetics of VN/Co5.47N. Meanwhile, X-ray diffraction in combination with transmission electron microscopy discloses abundant atomic defects in the VN/Co5.47N coupling interface, and such interfacial disordered atoms and/or dangling bonds act as extra active sites for effective ORR catalysis. Benefiting from the interfacial electronic and atomic advantages, the as-prepared VN/Co5.47N realizes an ultralow half-wave potential of 0.81 V, high selectivity, and favorable stability. More importantly, the outstanding ORR performances of VN/Co5.47N endow the homemade Zn-air battery with VN/Co5.47N as an air cathode to afford outstanding performances in specific discharge capacity, power density, and discharge-charge cycle stability. This work paves the way for insight into the atomic interface-performance relationship in ORR, and meanwhile, these findings can be extended to design other active catalysts.