In situ formed CuInS2/SnS2 hybrid on foam-like nickel as bifunctional electrode for water splitting

Developing low-cost, efficient and robust non-noble electrocatalysts for overall water splitting is of primary importance in the future of energy solutions. In this paper, the CuInS2/SnS2 composite nanosheets array on foam-like nickel (CuInS2/SnS2/NF) was synthesized in situ via a facile hydrothermal approach and the successive ionic layer adsorption reaction method (SILAR). The as-obtained heterostructure array exhibits high electrocatalytic activity toward HER with a small overpotential of 78, 191 and 337 mV at 10, 20, and 100 mA/cm2, and remarkably enhanced OER activities with the overpotential of 258, 286 and 382 mV at 10, 20, and 100 mA/cm2 in an alkaline electrolyte. Meanwhile, the CuInS2/SnS2/NF electrode shows a lower tafel slope and outstanding electrochemical stability in both the HER and OER, displaying an excellent application foreground in the field of electrocatalytic water splitting. Moreover, the overall water splitting performance of CuInS2/SnS2/NF electrode was studied, in which the electrode serves as both the anode and cathode, and at a comparatively low voltage of 1.79 V, the current density achieves 100 mA/cm2. This study establishes a primitive strategy for obtaining mixed multimetal sulfides on self-supporting porous metal substrate, which can be used as an efficient bifunctional electrocatalyst, and is of great practical significance in future energy application.