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

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 inex-pensive and efficient catalysts. Herein, we propose a metal-free biphenylene nanosheet, a recently proposed two-dimensional (2D) carbon allotrope, as an excellent HER electro-catalyst. The dynamical and thermal stability of biphenylene nanosheet is validated through phonon dispersion and abinitio molecular dynamics (AIMD) calculations, respec-tively. At a low H coverage (1/54), the biphenylene nanosheet shows excellent catalytic activity with the Gibbs free energy (DGH*) of 0.082 eV. The Bdoping and C-vacancy in biphenylene further improve DGH* 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.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.