Detection of HF and H2S with pristine and Ti-embedded twin graphene: A density functional theory study

Abstract

Adsorption of HF and H2S on pristine and Ti-embedded twin graphene sheets is studied utilizing density functional theory (DFT) calculations to understand the capability of these materials for detecting these toxic gases. The optimal configurations, adsorption energies, and charge transfer are calculated. The small adsorption energies and large adsorption distance indicated that HF and H2S are weakly physisorbed on pristine twin graphene sheets. The adsorption strength increases after decorating twin graphene with a Ti atom. Electronic properties including band structures and density of states reveal that both pristine and Ti-embedded twin graphene sheets possess semiconducting properties. Adsorption of HF and H2S decreased the energy band gap of both pristine and Ti-embedded twin graphene sheets. It was found that embedding Ti to twin graphene increases the sensitivity of the material to HF and H2S adsorption, which is mainly due to the stronger integration between adsorbed molecules and Ti-embedded sheet. Hence, current research introduces Ti-embedded twin graphene as a high sensitive, and low cost gas sensor candidate for detecting the toxic gases.