Plasmon enhanced photocatalytic activity of Au@TiO 2 -graphene nanocomposite under visible light for degradation of pollutants

Abstract Au@TiO 2 -Graphene (GR) nanocomposite was prepared using photocatalytic reduction method. TiO 2 -GR nanocomposite was synthesized under UV irradiation of deaerated ethanolic suspension of TiO 2 . The nanocomposite was calcined at 400 ∘ C followed by loading of highly dispersed Au nanoparticles throughout the deposition-precipitation method. The Au@TiO 2 /GR was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, diffuse reflectance spectroscopy, transmission electron microscope and the BET surface area measurements. It was found that Au-TiO 2 -GR and TiO 2 -GR nanoparticles have smaller crystalline size and higher surface area than pure TiO 2 . Presence of highly dispersed Au nanoparticles on the TiO 2 structure and graphene as supporter caused absorption shift into the visible region. The incorporation of GR and Au into TiO 2 significantly enhanced the electron transport and therefore impeded the charge recombination of excited TiO 2 . Evaluation of photocatalytic activity by degradation of Acid Blue 92 under the UV and visible light verified the superior photocatalytic performance of the Au@TiO 2 -GR nanocomposite.