Constructing Complementary Catalytic Components on Co4N Nanowires to Achieve Efficient Hydrogen Evolution Catalysis

Cobalt nitrides with a high ratio of cobalt-cobalt interaction have been extensively explored as electrocatalysts for hydrogen evolution reaction (HER) catalysis. However, the tilted orbital orientation and limited empty d-orbitals above the Fermi level (E-F) result in unfavorable water adsorption/activation. Herein, facile interfacial engineering by in situ growing of MoN particles on Co4N nanowire arrays to explore the interfacial synergistic mechanism for boosting HER catalysis is developed. The overpotential of the prepared MoN-Co4N at 10 mA cm(-2) is only 45.1 mV, which is substantially better than the pristine Co4N (207 mV). According to density functional theory (DFT) calculations, MoN with vertical orbital orientation and more empty d-orbitals above E-F contributes to water adsorption and activation, while the Co4N surface is responsible for the adsorption/desorption of the intermediate H. Understanding the synergistic effects of each catalytic component at the atomic levels offers valuable insights for rational design of efficient HER catalysts and beyond.