Synthesis of reduced graphene oxide functionalized with methyl red dye and its role in enhancing photoactivity in TiO2–IL/WO3 composite for toluene degradation

A nanostructured composite material was produced through sol–gel-assisted ionic liquid (IL) synthesized TiO 2 , WO 3 and functionalized reduced graphene oxide (FRGO), respectively. IL was selected and used as shape and size controller in TiO 2 synthesis as well. GO nanosheets were functionalized with ( E )-2-[4-(dimethylamino) phenyl] benzoic acid (methyl red dye) in order to absorb more light. The products were characterized using X-ray diffraction spectroscopy, scanning electron microscopy, transmission electron microscopy, N 2 adsorption–desorption methods, FTIR, Raman, photoluminescence and X-ray photoelectron spectroscopy. The photocatalytic activity of TiO 2 –IL/WO 3 /FRGO composite in toluene degradation under visible-light irradiation was evaluated by gas chromatography. The prepared composite demonstrated significant toluene degradation (ca. 74%) after only 2 min of reaction in comparison to TiO 2 –IL/WO 3 composite (51%), TiO 2 –IL (40%) and pure TiO 2 (17%). These results are due to the combination of FRGO and WO 3 with TiO 2 by their properties like stability, high surface area and low band gap.