Novel Ti-decorated borophene x_3 as potential high-performance for hydrogen storage medium

摘要

Recently, an eye-catching boron monoatomic layer named chi(3) has been synthesized in lab and subsequent studies have confirmed its high stability. As a novel borophene, the theoretical explorations prior to the experiments are crucial for its applications. In the present work, we perform systematically theoretical calculations on this new synthesized layer for the capacity of hydrogen storage. By decorating the nanosheet with Ti atoms, the hydrogen storage capacity is dramatically enhanced, and Ti atoms tend to be dispersed on the borophene chi(3), since an energy barrier larger than 1.15 eV prevents the aggregation of Ti atoms. Ultimately, up to eight hydrogen molecules are stably bound to each Ti atom in B16Ti4 (Ti atoms decorated two-side of 2 x 2 borophene chi(3) supercell) with an average adsorption energy of 0.199 eV/H-2, corresponding to the highest capacity of hydrogen storage with a gravimetric density of 15.065 wt%. The charge transfer in B16Ti4 introduces a built-in electric field and leads to the polarization of H-2 molecules, consequently enhances the hydrogen storage capacity of chi(3). (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.