Table 1. Summary of HER activities of porous MoC _x nano-octahedrons.

Electrolyte	Onset η (mV versus RHE)	η at j=1 mA cm−2 (mV versus RHE)	η at j=10 mA cm−2 (mV versus RHE)	Tafel slope (mV per decade)	Exchange current density (mA cm−2)
0.5 M H2SO4	~25	87	142	53	0.023
1 M KOH	~80	92	151	59	0.029

HER, hydrogen evolution reaction.