Highly dispersed NiMo@rGO nanocomposite catalysts fabricated by a two-step hydrothermal method for hydrogen evolution

Exploring and designing a high-performance non-noble metal catalyst for hydrogen evolution reaction (HER) are crucial for the large-scale application of H₂ by water electrolysis. Here, novel catalysts with NiMo nanoparticles decorated on reduced graphene oxide (NiMo@rGO) synthesized by a two-step hydrothermal method were reported. Physical characterization results showed that the prepared NiMo@rGO-1 had an irregular lamellar structure, and the NiMo nanoparticles were uniformly dispersed on the rGO. NiMo@rGO-1 exhibited outstanding HER performance in an alkaline environment and required only 93 and 180 mV overpotential for HER in 1.0 M KOH solution to obtain current densities of −10 and −50 mA·cm⁻², respectively. Stability tests showed that NiMo@rGO-1 had a certain operating stability for 32 h. Under the same condition, the performance of NiMo@rGO-1 can be comparable with that of commercial Pt/C catalysts at high current density. The synergistic effect between NiMo particles and lamellate graphene can remarkably promote charge transfer in electrocatalytic reactions. As a result, NiMo@rGO-1 presented the advantages of high intrinsic activity, large specific surface area, and small electrical impedance. The lamellar graphene played a role in dispersion to prevent the aggregation of nanoparticles. The prepared NiMo@rGO-1 can be used in anion exchange membrane water electrolysis to produce hydrogen. This study provides a simple preparation method for efficient and low-cost water electrolysis to produce hydrogen in the future.