Ultrafine Co3O4 nanoparticles-engineered binary metal nitride nanorods with interfacial charge redistribution for enhanced water splitting

Abstract

Herein, an efficient bifunctional electrocatalyst based on binary metal nitride (Zn₃N₂–Co₂N) nanorod arrays decorated with ultrathin Co₃O₄ nanoparticles is prepared to improve overall water splitting performance. Notably, a charge redistribution process occurs at the heterointerface between the host metal nitride and the guest Co₃O₄, resulting in the regulation of both their electronic structures to facilitate the reaction kinetics of hydrogen/oxygen evolution reaction (HER/OER). Using the material to catalyze the HER, current density of 10 and 50 mA cm⁻² are delivered at small overpotential of 80.5 and 121.7 mV, respectively. Similarly, for OER, under the action of the material, overpotential of only 271.7 and 335.7 mV, respectively, is required to achieve 10 and 50 mA cm⁻². Thus, an electrolyzer is assembled with the material as both cathode and anode, and shows high performance with a small cell voltage of 1.59 V at 10 mA cm⁻², and excellent stability.