Theoretical insights into hydrogen sensing capabilities of black phosphorene modified through ZnO doping and decoration

This paper has addressed the sensing capabilities of black phosphorene (BP) modified through ZnO decoration and doping at the HSE06/TZVP level of theory. For the ZnO-decorated (PZ) material, the hydrogen molecule adopted a parallel configuration with respect to the Zn-O bond. On the two ZnO-doped (ZP) nanosensors, however, the first hydrogen molecule preferred the placement above the Zn atom. An ideal substitution of ZnO with retrieving lattice structures of defective BP to the pristine arrangement was highly favored (-127.03 kcal/mol). The stabilization of hydrogen molecules on all sensors was relatively weak (up to -3.03 kcal/mol), however. Indirect band structures were observed for both PZ (decorated) and ZP (doped) sensors. The PZ sensor performed quite better (with a gas sensitivity of 410.0%) compared to the ZP counterpart. The work function was decreased in all cases after the incorporation of ZnO or the adsorption of hydrogen molecules. The obtained data confirmed that the pristine BP could be converted into a reusable hydrogen sensor through ZnO doping and particularly decoration, having a recovery time of 43 ps at room temperature. We also made an account of the effect of temperature, selectivity, surface diffusion, and the electronic properties of the improved sensors. Importantly, the PZ sensor was found to be more selective toward hydrogen. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.