Effect of Curvature on the Hydrogen Evolution Reaction of Graphene

Graphene has been widely studied as an electrocatalyst for hydrogen evolution reaction (HER). However, pure flat graphene is catalytically inert in HER. In this work, we investigate the effect of curvature on the improvement in the catalytic activity of pure and doped graphenes. We find that the HER performance can be dramatically improved on waved-graphene due to localized chemical potential and Pt-analogous activity can be achieved at suitable compression. (1) For pure graphene, the calculated HER performance increases more than 50% as tuned by curvature due to reduced calculated Gibbs free energies. (2) For B- and N-doped graphene, their optimal HER catalytic ability occurs at low curvature conditions. (3) For metal-doped graphene, Mo-doped graphene exhibits excellent catalytic ability in HER at certain compressions. (4) For nitrogen-metal co-doped graphene, N–Ni and N–V co-doped graphenes can be tuned by curvature to show outstanding performance in HER with their exothermal formation energies. Our calculations demonstrate that the curvature plays a vital role in the improved HER activity of graphene and reveal the mechanism behind the improvement, which may provide guidance on the design of novel electrocatalysts for HER.