Polyvinyl alcohol protected Mo2C/Mo2N multicomponent electrocatalysts with controlled morphology for hydrogen evolution reaction in acid and alkaline medium

Herein, PVA-Mo 2 C/Mo 2 N nanospheres with surface roughness are synthesized via a polyvinyl alcohol (PVA) involved approach and used for hydrogen evolution reaction (HER). The average crystallite size of the PVA protected nMo 2 CN nanospheres (6.1 nm) is one third of that of the PVA-Mo 2 C/Mo 2 N without PVA protection (17.9 nm). At 10 mA cm −2 current density, the as-synthesized PVA-Mo 2 C/Mo 2 N nanospheres with surface roughness exhibit HER overpotentials of 132 mV and 142 mV with corresponding Tafel slope of 51.8 mV dec −1 and 50.4 mV dec −1 in acid and alkaline medium, respectively. This high apparent activity can be attributed to the high intrinsic activity originated from the adjacent surface active sites of Mo 2 C and Mo 2 N as well as the large ECSA of PVA-Mo 2 C/Mo 2 N nanospheres with surface roughness.