An Engineered Superhydrophilic/Superaerophobic Electrocatalyst Composed of the Supported CoMoSx Chalcogel for Overall Water Splitting

Abstract

The development of high‐efficiency electrocatalysts for large‐scale water splitting is critical but also challenging. Herein, hierarchical CoMoS x chalcogel was synthesized onto the nickel foam (NF) through in‐situ metathesis reaction and demonstrated excellent activity and stability in electrocatalytic hydrogen evolution reaction and oxygen evolution reaction in alkaline media, respectively. The high catalytic activity could be ascribed to the abundant active sites/defects in the amorphous framework and the promoted activity due to cobalt doping. Furthermore, superhydrophilic and superaerophobic properties of micro‐/nanostructured CoMoS x /NF promoted the mass transfer by facilitating access of electrolytes and ensuring fast release of gas bubbles. By employing CoMoS x /NF as bifunctional electrocatalysts, the overall water splitting device delivered 500 mA/cm 2 current density at a low voltage of 1.89 V and maintained without decay for 100 hours. This study presents the validity of synergistic optimization through compositions, structures and three‐phase interface towards large‐scale electrocatalytic applications.