Surface Sulfided NiMoO4 Rod-Like Electrocatalysts for Efficient Hydrogen Evolution Reaction

Abstract

As energy resources become increasingly scarce and environmental issues grow more pressing, hydrogen is emerging as a promising alternative to traditional fuels. In this work, rod-shaped NiMoO₄-Sx-c electrolytic water HER catalysts with surface particles attached were prepared by solvothermal vulcanization and calcination reduction based on the configuration of NiMoO₄ precursors with different NiMo atom ratios. NiMoO₄ Sx-c achieved current densities of 10 mA cm⁻² and 100 mA cm⁻² at overpotentials of 105 mV and 256 mV, respectively. At 100 mA cm⁻², the catalytic performance of the electrode did not change within 50 h, which proved that the treated catalyst had excellent stability. The excellent HER performance was attributed to the formation of cross-linked NiS₂ and MoS₂ heterostructures on its surface due to the vulcanization and calcination reduction processes, thereby increasing the H adsorption energy. Concurrently, during the vulcanization process, particles were deposited on the surface of the smooth rod-like structure, which improved the hydrophilic/hydrophobic properties of the catalyst, enhanced the diffusion of the electrolyte, and ensured the rapid release of bubbles. This research not only provides a new strategy for synthesizing efficient HER electrocatalysts but also promotes the development of efficient electrolytic water catalysts.

Graphical Abstract