Unique Hierarchical Mo2C/C Nanosheet Hybrids as Active Electrocatalyst for Hydrogen Evolution Reaction.

A facile and effective pyrolysis stratagem is proposed for the synthesis of hierarchical Mo2C/C nanosheet hybrids with sodium chloride (NaCl) crystals as a template. Large numbers of well-dispersed sheet-like Mo2C nanoparticles with the thickness of about 20 nm were anchored on the surface of carbon nanosheets. Benefiting from the ideal synergistic catalytic effect between the highly active sheet-like Mo2C nanoparticles and the conductive graphitic carbon, and strong charge transfer ability, the unique hierarchical sheet-like structure of Mo2C/C hybrids demonstrated excellent hydrogen evolution reaction (HER) performance in both alkaline and acid medias with small overpotential (125 mV for 10 mA cm-2 in 1 M KOH and 180 mV for 10 mA cm-2 in 0.5 M H2SO4) and remarkable stability, which is comparable to most reported non-noble metal HER electrocatalysts. With the simplicity and low-cost of the synthetic approach, the strategy presented here can be extendable to the preparation of other transition metal-based/carbon nanosheet hybrids for versatile applications.