Construction of echinoids-like MoS2@NiS2 electrocatalyst for efficient and robust water oxidation

Abstract

Boosting stability, durability, and intrinsic activity of electrocatalysts are the world’s concerns in promoting the application of oxygen evolution reaction (OER). Ni is averagely required in efficient electrocatalysts for OER, while Mo is familiar to hydrogen evolution reaction (HER). Herein, we introduce Mo into electrocatalysts for OER and synthesize an echinoids-like MoS2@NiS2 electrocatalyst with unique morphology, which demonstrates rapid reaction kinetics and impressive catalysis activity. Furthermore, the electrocatalyst shows low overpotentials of 356 mV at 100 mA cm−2 as well as a Tafel slope of 82.6 mV dec−1 in alkaline media. Meanwhile, the electrocatalyst has a large double-layer capability (Cdl) and electrochemically active surface areas (ECSA) values. The OER performances remarkably enhanced with the help of MoS2 affiliation. Owning to the Ni compounds as the substrate, the catalyst can maintain a good stability in alkaline solution even after 10 h of chronoamperometry test at 1.51 V. Our study proposes a feasible way to obtain a high-efficient and robust OER electrocatalyst for the practical application.