Nitrogen-doped or boron-doped twin T-graphene as advanced and reversible hydrogen storage media

Abstract

Two-dimensional (2D) carbon-based (C-based) materials can be regarded as potential hydrogen storage media because of their splendid chemical stability and high specific surface area. Recently, a new 2D carbon allotrope twin T-graphene (TTG) with three-atomic layers thick is reported. Motivated by the above exploration, we employed Density Functional Theory (DFT) computational studies to systematically solve twin T-graphene, nitrogen-doped (N-doped) TTG and boron-doped (B-doped) TTG, and evaluate their performance in hydrogen storage at operable thermodynamic conditions. Six hydrogen molecules were adsorbed on the pristine twin T-graphene, and the hydrogen storage capacity was 7.69 wt%. After N doping and B doping, the twin T-graphene both can adsorb eight hydrogen molecules, and the hydrogen storage capacity was increased to 9.88 wt% and 10.06 wt%, respectively. In addition, we found that the hydrogenation/dehydrogenation (desorption) temperature is predicted to be 241 K. The desorption temperature and desorption capacity of H2 under practical conditions further indicate that it can be used as a reversible hydrogen storage media. This study reveals that twin T-graphene, N-doped and B-doped twin T-graphene are promising hydrogen storage materials with splendid desorption temperature, ideal adsorption energy and high hydrogen storage capacity. Meanwhile, this research will expand the application of heteroatom-doped carbon-based materials.