Plasmonic effect of metal nanoparticles on the photocatalytic properties of TiO₂/rGO composite

Abstract

In this work, the plasmonic effect of Au and Ag nanoparticles in the heterostructure photocatalyst system (TiO2/rGO) was studied. The laser ablation approach was applied to synthesize Au and Ag nanoparticles to eliminate impurity influence in this plasmonic study. Characterizing tools such as SEM, TEM, XRD, Raman, UV–vis spectral techniques were applied to obtain morphological information and optical properties of the nanocomposites. Photocatalytic properties of ternary nanocomposities such as, TiO2/rGO/Ag and TiO2/rGO/Au, were evaluated against Methylene blue and Congo red dyes with changing concentration of plasmonic nanoparticles (Au and Ag) and it was founded that the nanocomposite with the concentration of 10–11 mol/L Au NPs in TiO2/rGO has the best photocatalytic activity. EIS study indicated that a significant decrease in resistance Rp (109 Ohms) was observed for TiO2/rGO at 10-11 mol/Lconcentration of Au and its lifetimes is 0.0118 s, supporting that TiO2/rGO/Au has the best photocatalytic activity at 10–11 mol/L Au in the TiO2/rGO nanocomposites.