Mesoporous NiCo alloy/reduced graphene oxide nanocomposites as efficient hydrogen evolution catalysts

Water electrolysis is a clean and efficient route for producing high-purity hydrogen. Developing highly efficient, stable and inexpensive electrocatalysts to replace Pt is currently a major challenge for the widespread application of water splitting. Herein, we report a facile and novel strategy for the synthesis of mesoporous NiCo alloy nanoparticle/reduced graphene oxide (MNiCo/rGO) composites via electroless deposition technique. Owing to the synergistic interaction of Ni and Co, the mesoporous structure of NiCo alloy, and the optimized combination of the mesoporous NiCo with rGO, the obtained optimal MNi₆₃Co₃₇/rGO₅ catalyst exhibits outstanding electrocatalytic performance for hydrogen evolution reaction (HER) with a low overpotential of 115 mV to reach the current density of 10 mA cm^-2, and a small Tafel slope of 45 mV dec^-1, as well as a high durability in alkaline solution. These remarkable merits make it a favorable alternative to noble metal Pt-based catalysts for HER, thereby further promoting the development of non-noble metal electrocatalysts.