The effect of oxygen functional groups on TiO2/RGO composites for the degradation of unsymmetrical dimethylhydrazine

Compared with traditional titanium dioxide (TiO2), the addition of graphene can dramatically enhance the absorption and photocatalysis property. To explore the influence of graphene on TiO2/RGO composite, we investigated the nature of composite based on the first principles calculation. Newly-formed Ti-O bonds and hydrogen bonds in the interface were conducive to the formation of stable structures. The potential photoelectron trap state of C and the contribution from the orbitals of the oxygen functional groups in TiO2/ RGO could hinder the electron-hole recombination. Degradation experiments of gaseous unsymmetrical dimethylhydrazine (UDMH) were also conducted in our research, indicating that TiO2/RGO composite could improve the conversion rate under UV light. Then, the adsorption capacity of UDMH adsorbed on TiO2/RGO was discussed. It was found that hydrogen bond, especially between hydroxyl group and tertiary amine on UDMH, was helpful to promote the adsorption. The Bader charge and charge density difference were compared to show the charge transfer in the absorption systems and the cause of the Ti-O -C bond formation. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).