Metallic Mo2C anchored pyrrolic-N induced N-CNTs/NiS2 for efficient overall water electrolysis

Abstract

Transition metal disulfides have shown promising catalytic activity, while carbides possess high stability toward water electrocatalysis. It is an ideal way to develop high-performance electrocatalysts with enhanced activity and stability by combining the two compounds together. Herein, we present a new strategy to promote the sulfidation process of Ni nanoparticles by modifying with MoxC, which can increase the ratio of pyrrolic-N and pyridine-N. Interestingly, the increase of pyrrolic-N can further promote the metal Ni completely sulfurized into NiS2 nanoparticles. The as-synthesized material of NiS2 nanoparticles coated with self-grown carbon nanotubes modified by Mo2C can serve as bifunctional electrode, which achieves a current density of 10 mA cm−2 at a voltage of 1.52 V to generate H2 and O2 gases in alkaline media. Moreover, it can maintain 24 h stability at different current densities, which is more stable than N-CNTs/NiS2-Ni without Mo element. This finding provides a new method and idea for the development of new composite electrocatalysts toward more efficient water splitting.