Unraveling the strength interaction in a TiO2-Graphene photocatalytic nanocomposite synthesized by the microwave hydrothermal method

Abstract

Graphene oxide (GO) based composites were synthesized using a hydrothermal process, by these means, it was possible to tailor the loading of titanate nanotubes (TNTs) and TiO2 anatase particles in order to get insights into the photoactivity of the as-prepared photocatalyst. GO was prepared by the modified Hummers' method. The interactions stuck between titanium nanostructures and GO were studied by XRD, FESEM, FTIR, UV–vis and N2 physisorption along with computational studies using the DFT formalism on a graphene-TiO2 model. The photocatalytic performance was evaluated in the degradation of 4-clorophenol (4-CP) under UV light. The coexistence of anatase and titanate crystalline phases grown on the GO defects gave adsorptive and photocatalytic properties to the GO-based nanocomposites (TGO) and the favorable adsorption energy calculated by the DFT computational method showed that formyl acid surface groups on the tip area featured the main interaction of the TiO2-based photocatalyst. As a result, a photocatalyst with high surface area and functional sites was obtained, thus boosting the photoactivity and mass transfer properties to remove 4-CP from wastewater. Cycle voltammetry and electrochemical impedance measurements of the optimal TGO opened the possibility for using this material as a capacitor.