A highly active and durable electrocatalyst for large current density hydrogen evolution reaction

Splitting water under large current density is essential for efficient large-scale production and commercial utilization of hydrogen. However, the performance of the available electrocatalysts for hydrogen evolution reaction (HER) is far from satisfactory under large current density in alkaline electrolyte. Here we report a remarkably active and durable electrocatalyst, long and dense MoS₂/Ni₃S₂ co-axial heterostructure nanowires on nickel foam (NF). Notably, it requires only 182 and 200 mV overpotential to achieve large current density of 500 and 1000 mA cm^-2, respectively, in alkaline solution, which are far superior to those of Pt/C-NF (281 and 444 mV) and the reported best non-noble metal catalysts (191 and 220 mV). The physical origin for this extraordinary HER performance is analyzed, which provides a useful guide for structure design of electrocatalysts to further improve their performance.