Cobalt-molybdenum bimetallic phosphide grown in situ on nickel foam as a bifunctional electrocatalyst for efficient water splitting

The design of low-cost, efficient, and non-precious metal catalysts for both cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER) in overall water splitting is a necessary and urgent task. In this paper, Co-Mo-P nanopillar array catalysts were successfully prepared on three-dimensional nickel foam (Co-Mo-P/NF) by hydrothermal and phosphorylation methods. The vertically aligned nanopillar structure provides a relatively high specific surface area, which can provide an abundance of active sites and facilitate the penetration of the electrolyte and increase the electron transfer rate. Electrochemical tests have shown that Co-Mo-P/NF exhibits excellent alkaline HER and OER performance with ultralow overpotential as low as 37 mV for HER and 258 mV for OER at a current density of 10 mA cm⁻². Moreover, the Co-Mo-P/NF exhibits outstanding electrochemical performance with a cell voltage down to 1.58 V to obtain 10 mA cm⁻². This work demonstrated the remarkable potential of Co-Mo-P/NF in catalyzing water splitting process.