Controllable synthesis of TiO2 chemically bonded graphene for photocatalytic hydrogen evolution and dye degradation

The present work deals with preparation of graphene chemically bonded to TiO2 film (G-TiO2), which gives rise to Ti-O-C bond pattern. The structural and morphological properties of the synthesized G-TiO2 nanocomposite were studied by X-ray diffraction (XRD), Raman spectrospcopy, SEM, TEM, EDAX and Atomic force microscopy (AFM) techniques. Observable increase in the activity of chemically bonded G-TiO2 catalyst for photochemical H2 evolution and degradation of Evans blue (EB) after solar light irradiation due to efficient migration photo-induced electrons and electrostatic interaction between G and TiO2 coating. G-TiO2 shows enhanced catalytic activity with the liberation of 3.85 mmol g−1 of H2 through water splitting reaction as compared to 0.76 mmol g−1 of H2 evolution for standard P25. It becomes completely colorless for a period of 60 min of irradiation with solar light and shows respectable catalytic activity even after recycling it five times. The G-TiO2 composite is a non-toxic, stable, economical material that can be applied in photocatalytic applications.