Anti–corrosive FeO decorated CuCo2S4 as an efficient and durable electrocatalyst for hydrogen evolution reaction

Abstract An anti-corrosive FeO@CuCo2S4 electrocatalyst, with highly-active catalytic sites, is fabricated using a mild hydrothermal and magnetron sputtering growth technique. FeO@CuCo2S4 shows excellent hydrogen evolution reaction (HER) in an alkaline KOH electrolyte with a low overpotential of 107 mV at 10 mA/cm2 and a small Tafel slope of 136 mV/dec. Moreover, long-term stability tests at various current densities, up to 100 mA/cm2, demonstrate its excellent sustainability. The excellent HER catalytic performance and stability are attributed to the synergy between FeO and CCS elucidated by density functional theory, which is aroused from electrocatalytically activated surface, anti-corrosive surface, and the improved electronic conductivity.