Pristine [formula omitted] monolayer as highly efficient reversible hydrogen storage material under ambient temperature and pressure

Abstract

The advent of 2D materials has made physisorption-based H2 storage a promising alternative to conventional techniques involving high pressure and cryogenic temperature. However, most of the reported 2D materials require the addition of metal atoms or the application of an electric field to meet the U.S. Department of Energy (DoE) target of 6.5% gravimetric storage capacity for practical usage. Based on density functional theory (DFT), we show 2D BC6N, in its pristine form, demonstrates a storage capacity of 11.11 wt% with a binding energy of 0.139 eV per H2. At 1 atm pressure, the desorption occurs at temperatures above 118.23 °C, making the storage fully reversible at experimentally conceivable temperatures. The study of the desorption temperatures at varied external pressures indicates a broad operational range for commercial usage. Such high uptake capacity at ambient conditions makes pristine 2D BC6N an ideal candidate for metal-free, reversible hydrogen storage.