Porous NiMoO4−x/MoO2 hybrids as highly effective electrocatalysts for the water splitting reaction

The rational design of an optimal bifunctional electrocatalyst for water splitting with low cost and high activity is greatly desired for the realization of efficient conversion and storage of sustainable energy. Herein, a novel NiMoO4−x/MoO2 hybrid electrocatalyst with atomic-level coupled nanointerfaces and plentiful Mo5+ species is reported. The NiMoO4−x/MoO2 electrocatalyst shows excellent electrocatalytic performances for both the HER and the OER in alkaline media with Tafel slopes of 31 and 69 mV dec−1, and a current density of 10 mA cm−2 at overpotentials of 41 and 233 mV for the HER and OER, respectively. The NiMoO4−x/MoO2 can further work as bifunctional electrode materials for overall water splitting and achieves a current density of 10 mA cm−2 at a voltage of only 1.56 V.