One-step preparation of cobalt-doped NiS@MoS2 core-shell nanorods as bifunctional electrocatalyst for overall water splitting

Abstract

Development of transition metal-based catalysts to replace precious metal catalysts has significant meaning for overall water splitting. Here, we prepared cobalt-doped NiS@MoS₂ core-shell nanorods (Co-NiS@MoS₂) as bifunctional catalyst through a simple one-step hydrothermal method. Co-NiS@MoS₂ catalyst could achieve brilliant electrocatalytic performance for hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and overall water splitting. And Co-NiS@MoS₂ catalyst manifested small overpotentials at 50 mA cm⁻² for both HER (139.9 mV) and OER (170.6 mV) catalytic performance in 1 M KOH solution. In addition, it displayed a cell voltage of 1.54 V at 50 mA cm⁻² for overall water splitting, which is comparable with or surpasses the reported catalysts in the literatures. And Co-NiS@MoS₂ catalyst had superior stabilities for HER, OER and overall water splitting in 1 M KOH due to its unique core-shell structure and synergistic effects of NiS nanorods and MoS₂ nanosheets.