Tailored Ce-Doped\nNiMoO<sub>4</sub>/MoS<sub>2</sub>@rGO Nanoarchitectures for Sustainable\nElectrochemical Water Splitting\nin Alkaline Medium

In this study, we report a meticulously engineered electrocatalyst\nemploying a multicomponent system consisting of Ce-doped NiMoO<sub>4</sub> nanorods as the primary component. The Ce-doped NiMoO<sub>4</sub> nanorods were primarily integrated with two-dimensional (2D)\nMoS<sub>2</sub> nanosheets and further modified with rGO, significantly\nenhancing the charge transport in the interfacial region of the hybrid\nnanoarchitecture (Ce-NiMoO<sub>4</sub>/MoS<sub>2</sub>@rGO). Cerium\ndoping, combined with the multicomponent architecture, targeted toward\nenhancing the density of active sites and conductivity, which promoted\nefficient water decomposition. The synergistic effect of doping and\nheterostructure strategies resulted in efficient hydrogen evolution\nreaction (HER) and oxygen evolution reaction (OER) performance of\nthe Ce-NiMoO<sub>4</sub>/MoS<sub>2</sub>@rGO electrocatalyst. This\nelectrocatalyst demonstrated impressive bifunctional activity with\na low overpotential of 153 mV for the benchmark current of 10 mA cm<sup>–2</sup> and a Tafel slope of 82 mV dec<sup>–1</sup> for the HER. For the OER, an overpotential of 278 mV was observed\nfor the cathodic current of 20 mA cm<sup>–2</sup> with a Tafel\nslope of 114 mV dec<sup>–1</sup>. Additionally, our electrolyzer,\nutilizing Ce-NiMoO<sub>4</sub>/MoS<sub>2</sub>@rGO as electrodes,\nacquired a total current density of 10 mA cm<sup>–2</sup> at\na full-cell voltage of 1.58 V. Moreover, the Ce-NiMoO<sub>4</sub>/MoS<sub>2</sub>@rGO heterostructure exhibited prolonged durability with minimal\ndeactivation even after continuous operation for 24 h.