Constructing highly active interface between layered Ni(OH)2 and porous Mo2N for efficient electrocatalytic oxygen evolution reaction

Abstract

Layered Ni(OH)2 materials are cheap and efficient electrocatalyst for water splitting. However, pristine Ni(OH)2 materials usually show poor activity due to the low activity sites and poor conductivity in electrochemical reactions. Herein, layered Ni(OH)2 nanosheets are grown on the porous Mo2N particles for improved interfacial active sites and enhanced conductivity in the oxygen evolution reaction (OER). The OER overpotential of the optimized Mo2N/Ni(OH)2 composite material is distinctly reduced compared with pristine Ni(OH)2. In addition, the optimized Mo2N/Ni(OH)2 composite material exhibits favorable durability in alkaline electrolyte. Further electrochemical investigation reveals that the Mo2N/Ni(OH)2 composite materials produce increased charge transfer capability and electrochemical active surface area. Theoretical calculation study demonstrates that a redistribution of electron occurred at the interface of Ni(OH)2 and Mo2N, which results in the decrease of energy barrier for the adsorption of OER reactive intermediates at the interfacial atoms. The enhanced performance of OER is thus mainly come from the constructed interface between layered Ni(OH)2 and porous Mo2N. This work gives a feasible method to develop cheap and efficient electrocatalysts for water splitting.