Enhancement in the Photocatalytic Activity of Au@TiO2Nanocomposites by Pretreatment of TiO2with UV Light

A novel, efficient and controlled protocol for the synthesis and enhanced photocatalytic activity of nanocomposite is developed. (P25) was pretreated by employing UV light ( = 254 nm) and the pretreated was uniformly decorated by gold nanoparticles (AuNPs) in presence of sodium citrate and UV light. UV pretreatment makes the activated, as electrons were accumulated within the in the conduction band. These accumulated electrons facilitate the formation of AuNPs which were of very small size (2-5 nm), similar morphology and uniformly deposited at surface. It leads to formation of stable and crystalline nanocomposites. The rapidity (13 hours), monodispersity, smaller nanocomposites and easy separation make this protocol highly significant in the area of nanocomposites syntheses. As-synthesized nanocomposites were characterized by TEM, HRTEM, TEM-EDX, SAED, XRD, UV-visible spectrophotometer and zeta potential. Dye degradation experiments of methyl orange show that type I ( nanocomposites in which was pretreated with UV light) has enhanced photocatalytic activity in comparison to type II ( nanocomposites in which was not pretreated with UV light) and (P25). This shows that pretreatment of provides type I a better catalytic activity.