Superhydrophilic carbon-modified NiMoO4 for highly efficient overall water splitting

The development of affordable and efficient alternatives to precious metal-based electrocatalysts remains a key challenge for water electrolysis. In this study, carbon-modified NiMoO 4 /NF nanorods were prepared via a hydrothermal method combined with low-temperature vacuum carbonization. In 1 M KOH, the catalyst exhibits overpotentials of 34 mV and 142 mV for hydrogen evolution reaction (HER), 161 mV and 364 mV for oxygen evolution reaction (OER) at 10 and 50 mA cm −2 , respectively. Moreover, the catalyst requires low overall water splitting (OWS) potential of 1.53 V to achieve 10 mA cm −2 . Density functional theory (DFT) calculations demonstrate that carbon incorporation reduces water adsorption energy, optimizes the adsorption of H* intermediates on Mo sites, and enhances the synergistic interaction between Ni and Mo elements. This work demonstrates that low-temperature carbonization offers a viable route for fabricating a carbon-modified bifunctional electrocatalyst.