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

Abstract

• Controllable synthesis of graphene chemically bonded to TiO 2 . • G-TiO 2 showed 3.85 mmol g −1 of H 2 through water splitting reaction. • Evans Blue dye becomes colorless for a period of 60 min of irradiation with solar light. • Mechanism of H 2 evolution and dye degradation is discussed. The present work deals with preparation of graphene chemically bonded to TiO 2 film (G-TiO 2 ), which gives rise to Ti-O-C bond pattern. The structural and morphological properties of the synthesized G-TiO 2 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-TiO 2 catalyst for photochemical H 2 evolution and degradation of Evans blue (EB) after solar light irradiation due to efficient migration photo-induced electrons and electrostatic interaction between G and TiO 2 coating. G-TiO 2 shows enhanced catalytic activity with the liberation of 3.85 mmol g −1 of H 2 through water splitting reaction as compared to 0.76 mmol g −1 of H 2 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-TiO 2 composite is a non-toxic, stable, economical material that can be applied in photocatalytic applications.