Mott Schottky CoS x -MoO x @NF heterojunctions electrode for H 2 production and urea-rich wastewater purification

The sluggish kinetics of oxygen evolution reaction (OER) is the bottleneck of alkaline water electrolysis. The urea oxidation reaction (UOR) with much faster kinetics was to replace OER. To further promote UOR, a heterojunction structure assembled of CoS and MoO was established, and then its superior catalytic activity was predicted by DFT calculation. After that, an ultra-thin CoS -MoO @nickel foam (CoS -MoO @NF) electrode with a Mott-Schottky structure was prepared via a facile hydrothermal method, followed by a low-temperature vulcanization. Results highlighted CoS -MoO @NF electrode presented a superior performance toward UOR, OER, and H evolution reaction (HER). Notably, it exhibited excellent electrocatalytic performance for OER (1.32 V vs. RHE, 10 mA cm ), UOR (1.305 V vs. RHE, 10 mA cm ), and urea-assisted overall water splitting with a low voltage (1.38 V, 10 mA cm ) when CoS -MoO @NF electrode served as both anode and cathode. It is promising to use CoS -MoO @NF in an electrochemical system integrated with H generation and urea-rich wastewater purification.