Preparation of graphene–TiO2 nanocomposite and photocatalytic degradation of Rhodamine-B under solar light irradiation

Abstract

ABSTRACTGR–TiO2 nanocomposite was prepared by simple chemical method using graphene oxide and titanium isopropoxide (Ti [OCH (CH3)2]4) precursors. The crystalline nature of the composite was characterised by powder X-ray diffraction and the intercalation was explained by Raman spectroscopy. The morphology of the composite was analysed by field emission scanning electron microscopy. The elemental and quantitative measurement of the composite was determined by electron dispersive spectroscopy. The shape and size of the particle was measured by transmission electron spectroscopy and high resolution spectroscopy. The surface area and elemental composition of the composite was studied by using Brunauer–Emmett–Teller (BET) method and X-ray photoelectron spectroscopy. Photo-generated electrons were studied by photoluminescence spectra. The photocatalytic activity of nanocomposite was investigated by the degradation of Rhodamine-B (Rh-B) in an aqueous solution under solar light irradiation. The GR–TiO2 demonstrates photocatalytic activity in the degradation with a removal rate of 98% under solar light irradiation as compared with pure TiO2 (42%), graphite oxide (19%), and mechanical mixture GR + TiO2 (60%) due to the increased light absorption intensity and reduction of electron–hole pair recombination with the intercalation of graphene and TiO2. The results indicated that the GR–TiO2 could be used as a catalyst to degrade Rh-B from coloured wastewater.