Flower-like nanosheets directly grown on Co foil as efficient bifunctional catalysts for overall water splitting.

Hydrogen generation through electrochemical water decomposition is a promising method to address the global energy crisis. Herein, we report the synthesis of a series of flower-like MoS/CoS composites on Co foil (MoS/CoS@CF) as high-performance electrochemical water-splitting catalysts in an alkaline environment. The flower-like array structure of MoS/CoS@CF not only increases the electrochemically active surface area of ​​the catalyst, but also facilitates the release of bubbles generated, resulting in enhanced catalytic activity. For the hydrogen evolution reaction, the MoS/CoS@CF electrode exhibits good stability and excellent catalytic activity in 1.0 M KOH (η = 105 mV), 1.0 M PBS (η = 92 mV) and 0.5 M HSO (η = 68 mV) solutions. For the oxygen evolution reaction, the electrode displays excellent stability and catalytic activity in 1.0 M KOH solution (η = 215 mV). When used for overall water splitting in 1.0 M KOH solution, MoS/CoS@CF achieves a current density of 10 mA cm at a low potential of 1.58 V and maintains it stably for 40 h. This study presents a simple method for preparing transition metal-based bimetallic composite catalysts for efficient hydrogen production.