Novel nanocomposite thin films for efficient degradation of Rhodamine B and Rhodamine 6G under visible light irradiation: Reaction Mechanism and Pathway studies

Abstract

The present investigation aims to synthesize the novel nanocomposite thin film and utilize the material to remove emerging dyes efficiently (i.e., Rhodamine B (R-B) and Rhodamine 6G (R-6G)), in an aqueous solution using LED visible light and UV-A light. A facile synthetic route was adopted to obtain the TiO<sub>2</sub>-supported bentonite and <i>in situ</i> decorated with Au nanoparticles (NPs) thin film. The advanced analytical techniques characterizes the materials. The laboratory scale reactor was utilized for efficient degradation of R-B and R-6G using thin film catalysts. The percentage removal of R-B was 54.13% (visible light) and 76.26% (UV-A light) and the R-6G, was removed 60.37% (visible light) and 84.68% (UV-A light) at the initial pollutant concentration of 0.5 mg/L and at pH 6.0 using the thin film photocatalyst. The parametric studies demonstrated the insights of degradation mechanisms in photocatalytic operations. A significant mineralization of these dyes is achieved, and the repeated use in reactor operations indicated the catalysts