Enhanced graphene oxide - titanium dioxide nanocomposite for photocatalytic applications

Photocatalytic degradation of organic dye contaminants has been an active research to solve industrial and environmental problems. This paper is devoted to discuss the Photocatalytic effectiveness of graphene oxide (GO) - titanium dioxide (TD) nanocomposite using Rhodamine-B (Rh-B) dye in an aqueous solution under solar light irradiation. Spherical TiO₂ nano particles of size 10 – 50 nm, synthesized by reactive plasma processing were used for this investigation. Improved Hummers method was used to synthesize graphene oxide. Graphene oxide (GO) - titanium dioxide (TD) nanocomposite was prepared using hydrothermal method. The crystalline nature of the composite was characterized by powder X-ray diffraction and the intercalation was explained by Raman spectroscopy. The morphology of the composite was analyzed by field emission scanning electron microscopy. 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 result showed that the GO - TiO₂ nanocomposite exhibited higher photocatalytic efficiency compared to the standard TiO₂ nanoparticles. The improved activity of GO - TiO₂ nanocomposite might be attributed to enhanced charge separation, efficient charge transportation, extended light absorption range and increased adsorption of dye. This nanocomposite has great potential for removal of environmental contaminant and could be applied for water purification. The proposed mechanism for this photocatalytic activity is shown as step by step process below. (author)