Nano-interfacial interactions in 2-D Ni3S2–Ni3N nanosheets for the hydrogen evolution reaction in an alkaline medium

Abstract

Sustainable hydrogen generation is a necessity for implementing the hydrogen economy of the future. In recent decades, the electrocatalytic hydrogen evolution reaction (HER) has attracted researchers’ interest as a key to understanding the mechanism of water electrolysis. Due to the sluggish kinetics of the hydrogen evolution reaction (HER) in alkaline environments, the development of an effective non-noble electrocatalyst for hydrogen generation is crucial but challenging. Herein, the heterostructure of Ni₃S₂–Ni₃N was prepared by a three-step synthesis procedure that consists of the formation of Ni₃S₂ on NF, the electrodeposition of Ni(OH)₂ over Ni₃S₂ and nitridation in the presence of ammonia. The interface formation between Ni₃S₂ and Ni₃N was successfully characterized using HRTEM analysis. The HER performance of the catalyst containing a Ni₃S₂–Ni₃N interface was found to be superior to that of individual Ni₃S₂ and Ni₃N phases. An overpotential of 96 mV was obtained for the Ni₃S₂–Ni₃N heterostructured catalyst at a current density of 10 mA cm⁻² with a Tafel slope value of 135 mV dec⁻¹. The catalyst was stable for 70 h with no loss under high current densities. This study offers a facile and dependable synthetic method for the rational design of extremely potent HER electrocatalysts in alkaline media.