Activation of metal-free porous basal plane of biphenylene through defects engineering for hydrogen evolution reaction

Abstract

The biggest challenge in the commercial application of electrochemical reduction of water through the hydrogen evolution reaction (HER) is hampered due to the scarcity of inexpensive and efficient catalysts. Herein, we propose a metal-free biphenylene nanosheet, a recently proposed two-dimensional (2D) carbon allotrope, as an excellent HER electrocatalyst. The dynamical and thermal stability of biphenylene nanosheet is validated through phonon dispersion and abinitio molecular dynamics (AIMD) calculations, respectively. At a low H coverage (1/54), the biphenylene nanosheet shows excellent catalytic activity with the Gibbs free energy (ΔGH∗) of 0.082 eV. The Bdoping and C-vacancy in biphenylene further improve ΔGH∗ to −0.016 eV and 0.005 eV, respectively. The interactions between the H atom and the nanosheet are explained through the relative position of the p-band center. Our study opens new possibilities to use non-metallic porous materials as highly efficient electrocatalysts for HER.