Facile preparation of multi-doped TiO2/rGO cross-linked 3D aerogel (GaNF@TGA) nancomposite as an efficient visible-light activated catalyst for photocatalytic oxidation and detoxification of atrazine

Abstract

The novel Ga, N, F co-doped TiO2@rGO aerogel (GaNF@TGA) nanocomposite was synthesized using a facile chemical method in the presence of ascorbic acid as a reducing agent and cross-linker. The XRD patterns indicated the lower intensity of the anatase XRD peak in doped-sample, which confirmed successful insertion of dopant atoms in the TiO2 lattice. FT-IR and Raman spectra confirmed the successful reduction of GO in the nanocomposite. The SEM and HRTEM images revealed the interconnected porous 3D network structure for the prepared TGA samples. Co-doping TiO2 with Ga, N and F caused considerable red shift in the absorption edge to the visible-light region. TGA catalyst had much higher photocatalytic activity than the plain TiO2 under visible-light irradiation due to the enhanced photogenerated charge separation for oxidation of atrazine (ATZ). The complete degradation of 40 mg/L ATZ was obtained in the photocatalytic oxidation process within 60 min with GaNF@TGA as catalyst. The reaction with OH at the surface of catalyst was the main mechanism contributed in degradation of ATZ in the developed photocatalytic process. The prepared catalyst showed a remarkable stability and simply separation for recycling. The cytotoxicity of fresh and photocatalytic-treated ATZ solutions assessed using the skin fibroblast cells (Hu02) indicated that treating ATZ solution in the developed visible-light photocatalytic reaction under optimum experimental conditions could considerably be detoxified. Accordingly, TGA is an efficient visible-light activated nanocomosite, which can be used as photocatalyts for enhanced degradation and detoxification of the emerging water contaminants.