Designing of efficient sensor based on H-decorated T-graphene for detection of hydrogen sulfide (H₂S): a first principle study

Here, we studied the adsorption of hydrogen sulfide (H₂S) on H-decorated T-graphene and its potential application as a gas sensor using density functional theory (DFT) calculations. To explore the mechanism behind the superior gas detection ability of H-decorated T-graphene, we examined the adsorption and diffusion of H₂S on this two-dimensional (2D) material. Our findings indicate that hydrogen sulfide physisorbs on H-decorated T-graphene with a small binding energy, minimal charge transfer from the substrate to the molecule, and a binding distance of 2.22 Å. The main contribution to the adsorption energy arises from van der Waals London dispersion interactions. We observed a reduction in the energy bandgap of the system upon adsorption of the hydrogen sulfide molecule, which leads to an increase in electrical conductivity. Bader charge analysis shows a minor electronic charge transfer from the substrate to the molecule. A low diffusion energy barrier of 0.162 eV suggests that H₂S molecules can diffuse rapidly. The negative adsorption energy, along with a short recovery time and low diffusion barrier, supports the potential for designing a gas sensor to detect hydrogen sulfide.