Hierarchical sulfide nanoarrays as an efficient bifunctional electrocatalyst for overall water splitting

The electrocatalytic water splitting technology is one of the efficient and environmentally friendly solutions to the problems of environmental pollution and energy shortage. In this paper, Co 9 S 8 @MoS 2 nanoarrays were successfully synthesized on nickel foam (NF) substrate by a stepwise hydrothermal process as a bifunctional catalyst for the unique electrolytic water splitting process. When the current density of 10 mA cm −2 is reached, only 1.52 V of voltage is required. When the alkaline water splitting reaction is continuously tested for 15 h, the corresponding voltage is almost unchanged and the retention rate is as high as 85%, which indicate the Co 9 S 8 @MoS 2 has good long-term stability.