Controllably constructed carbide/oxide heterointerfaces of molybdenum for efficient hydrogen evolution

The dependence of cathodic hydrogen evolution reaction (HER) on noble metal catalysts is a critical challenge to realizing the industrial-scale application of hydrogen production from electrochemical water splitting. Due to the excellent water dissociation catalytic ability of Mo 2 C and the high HER catalytic activity of MoO x , Mo 2 C/MoO x heterointerfaces are controllably constructed via hydrogen peroxide oxidation of Mo 2 C to achieve improved HER catalytic performance. On the Mo 2 C/MoO x heterointerface, protons generated by the Mo 2 C sites via water dissociation can be immediately reduced by adjacent MoO x sites via the Volmer step to promote the overall HER kinetics. As a result, the rationally designed heterointerface-rich Mo 2 C-O catalyst exhibits great HER activity with a low overpotential of 115 mV to deliver 10 mA/cm 2 current density. Along with great activity, the Mo 2 C-O catalyst also exhibits satisfying stability, confirming the promising application potential of the catalyst in industrial electrolysis systems.