Epitaxial growth of graphene on V8C7 nanomeshs for highly efficient and stable hydrogen evolution reaction

Exploring low-cost, non-noble hydrogen evolution reaction (HER) catalysts with remarkable activity in both acidic and alkaline media still remains an enormous challenge. Herein, a novel V8C7NMs/GR heterogeneous catalyst has been synthesized by epitaxial growth of graphene as efficient acidic and alkaline HER electrocatalyst, for the first time. Electrochemical tests and DFT calculations indicate that high activity of the exposed facet and low barrier energy for hydrogen adsorption and water dissociation could facilitate hydrogen evolution reaction. Owing to the electronic interactions between V8C7 and graphene at active hybrid interfaces, this catalyst shows high HER activity with a low overpotential at 10 mA cm(-2) (156 mV in 1 M KOH and 52 mV in 0.5 M H2SO4), a small Tafel slope (89.4 mV dec(-1) in 1 M KOH and 48.3 mV dec(-1) in 0.5 M H2SO4), and preferable durability in both acidic and alkaline media. This work opens up a new avenue for the epitaxial growth of graphene and exploring new-type active heterogeneous catalysts with advanced performance for HER. (C) 2018 Elsevier Inc. All rights reserved.