H2 adsorption over GeO2 monolayer: a theoretical study

The non-magnetic semiconducting GeO 2 monolayer is a potential candidate for gas sensing and hydrogen storage applications due to its large surface-to-volume ratio compared to the bulk materials and changing band gap for the adsorption of hydrogen molecules. In this work, the interaction of hydrogen molecule (H 2 ) with GeO 2 monolayer has been investigated using van der Waals density functional theory (vdW-DFT); the adsorption and surface diffusion energies of H 2 molecule have been calculated at different adsorption positions on the GeO 2 monolayer by applying revPBE-vdW functional. It has also been found that repulsion between two nearby H 2 molecules limits, how many H 2 molecules can fit inside one-unit cell of GeO 2 monolayer. The time evolution of the surface coverage, the number of adsorptions, diffusions, and desorption have been calculated by the Kinetic Monte Carlo (KMC) simulation code. To clarify the nature of the adsorption behaviour, Bader charge analysis, electron localization function (ELF), density of states (DOS) and band structure properties have been scrutinized.