Controllable synthesis of molybdenum carbide nanoparticles embedded in porous graphitized carbon matrixes as efficient electrocatalyst for hydrogen evolution reaction

Molybdenum carbide nanoparticles embedded in porous sheet-like graphitized carbon matrixes ( Mo2C/C) were controllably synthesized by a simple one-step solid reaction strategy. Remarkably, the porous graphitized carbon matrixes, which can efficiently restrain Mo2C nanoparticles from aggregation and improve the conductivity of the synthesized composites, are derived from the economic and environment-friendly agricultural by-product of cornstalks. Thanks to the novel structure, small size, large surface active area and high conductivity, the Mo2C/C composites exhibits superior performance when they are used as electrocatalyst in 0.5 M H2SO4 for hydrogen evolution reaction ( HER). The overpotential ( eta(10)) to achieve a current density of 10 mA cm (2) is low to 114 mV, and the Tafel slope is only 52 mV dec (1). Besides, the Mo2C/C composites show large exchange current density ( j(0)) of 0.286 mA cm (2). Furthermore, the synthesized sample behaves excellent stability over 20 h in acidic media for HER. More interestingly, the Mo2C/C composites behave comparable activities and stability in basic condition with those in acidic condition, which is meritorious. (C) 2016 Elsevier Ltd. All rights reserved.