Hydrogen evolution boosted by moderate Co 3 ZnC with current densities beyond 1000 mA cm -2 .

Co 3 ZnC can efficiently boost the activity of Co@N, O co-doped carbons for hydrogen evolution. The results show that moderate Co 3 ZnC plays key roles in achieving an appropriate weighted Co 3d band centre, enhancing charger transfer and thus optimizing the electrochemical active surface area. Thus, a low overpotential of ∼219 mV can drive a high current density of 1000 mA cm -2 under the favourable condition of moderate Co 3 ZnC.