Interface-Synergistically Enhanced Acidic, Neutral, and Alkaline Hydrogen Evolution Reaction over Mo2C/MoO2 Heteronanorods

Water electrolysis provides a promising way to achieve sustainable hydrogen production, which strongly depends on highly effective electrocatalysts for industrial application. Herein, Mo2C/MoO2 heteronanorods have been synthesized by means of a simple self-templated carbothermal reduction of polymolybdate-melamine precursor. Through manipulating the pyrolysis temperature, the optimal Mo2C/MoO2-650 heteronanorods show a low overpotential (168, 290, and 204 mV) to achieve current density of 10 mA cm–2 in 0.5 M H2SO4, 0.1 M PBS, and 1.0 KOH, respectively, which also presents a small Tafel slope (∼58 and 87 mV dec–1), high mass activity (115.4 and 33.8 A g–1 at η = 200 mA), and outstanding stability in 0.5 M H2SO4 and 1.0 KOH. The superior performance is mainly ascribed to the heterointerfaces between Mo2C and MoO2 promoting synergistic effects, quasi 1D nanostructures facilitating fast charge/mass transfer, and high electrochemical active surface area (ECSA) providing a large number of available sites. This work elucidates a feasible way by heteronanostructure engineering to explore and optimize electrocatalysts in energy chemistry.