Ultrarapid in Situ Synthesis of Cu2S Nanosheet Arrays on Copper Foam with Room-Temperature-Active Iodine Plasma for Efficient and Cost-Effective Oxygen Evolution

Developing simple and cost-effective methods for the rapid synthesis of oxygen evolution reaction (OER) electrocatalysts from earth-abundant elements is a highly desired yet challenging task. Herein we report a two-step strategy based on the use of a room-temperature- and atmospheric-pressure-active iodine DBD plasma and an anion exchange reaction for the in situ generation of 3D Cu2S nanosheet arrays on Cu foam (Cu2S/CF). Owing to the advantages of this plasma-based approach, and the extremely rapid anion exchange reaction between the generated CuI and S2–, synthesis of the Cu2S/CF OER catalyst can be accomplished within 6 min. The porous 3D catalyst exhibited prominent electrocatalytic activity and persistent stability (>10 h) for OER with an overpotential of 336 mV to drive a geometrical current density of 20 mA cm–2 in 1.0 M KOH, comparable to the performance of a noble-metal IrO2/CF electrode.