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.