First-Principles Study on the Adsorption of HF on Reduced Graphene Oxide

Hydrogen Fluoride (HF), a toxic and corrosive colorless gas, is hazardous to human health. It is important to explore sensor materials to detect HF and remove it. Reduced graphene oxide (rGO) is a new carbon-based material with large adsorption ability and high conductivity. In this work, the adsorption of HF on rGO is investigated by M06-2X functional. The adsorption of HF is stronger on rGO than graphene, which is attributed to the existance of active defect sites in rGO, e.g., epoxide, hydroxyl, carboxyl groups and the carbon atoms near these functional groups. O center dot center dot center dot H and F center dot center dot center dot H bonds form during the interaction between HF and rGO. The type and substituted site of oxygen-containing group in rGO affect the adsorption ability. Carboxyl group is much more attractive than epoxide and hydroxyl group in rGO for HF. Spin density plays an important part in enhancing the adsorption. The adsorption is the strongest for HF on rGO with carboxyl group connected to vacancy in our work.