Morphology-Engineered NiMo Alloy on Nickel Foam for Enhanced Hydrogen Evolution Reaction Performance

A nanoflower-like nickel-molybdenum alloy was synthesized by hydrothermal in situ growth of NiMoO₄ nanorod arrays on nickel foam (NF) followed by gas-phase re-reduction at 600 °C. The resulting structure has a uniform porosity and high specific surface area, which improves the availability of active sites and facilitates efficient electron and mass transport. SEM and XPS analyses confirm that the formed NiMoO₄ nanorods are uniformly distributed, which leads to significant optimization of their electronic structure. The electrochemical measurements revealed that the sample exhibited excellent hydrogen evolution reaction (HER) performance, with an overpotential as low as 127 mV at 100 mA cm^-2 and a Tafel slope of 124 mV dec^-1. CV and EIS showed that the sample had the largest electrochemically active surface area (121.3 mF cm^-2) among the samples treated at different temperatures, with the smallest charge transfer resistance. In addition, the catalyst maintained high stability after 45 h of continuous operation. These results highlight the potential of NiMo/NF as a highly efficient and durable HER catalyst to help advance hydrogen energy technology.