Amorphous Co-Mo-P film on nickel foam: A superior bifunctional electrocatalyst for alkaline seawater splitting.

Seawater splitting is a compelling avenue to produce abundant hydrogen, which requires high-performance and cost-effective catalysts. Constructing bimetallic transition metal phosphides (TMPs) is a feasible strategy to meet the challenge. Here, an amorphous Co-Mo-P film supported on nickel foam (Co-Mo-P/NF) electrode is developed with bifunctional properties for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline seawater. Corresponding results indicate that the introduction of Mo can improve the active sites and regulate the intrinsic activity. Such a Co-Mo-P/NF behaves with prominent electrocatalytic activity towards both HER and OER, demanding low overpotentials of 193 and 352 mV at 100 mA cm‒2 in alkaline seawater, respectively. Furthermore, the assembled electrolyzer demands a pronounced overall seawater splitting activity with a low cell voltage of 1.76 V to deliver 100 mA cm-2 presenting excellent durability without obvious attenuation after 24 h continuous stability test. This work expands the horizon to develop transition metal-phosphorus electrocatalysts with robust and efficient activity for overall seawater splitting.