An efficient time reductive photocatalytic degradation of carcinogenic dyes by TiO2-GO nanocomposite

• GO, T/G nanocomposite and TiO 2 NPs were prepared by environmental friendly method. • Photocatalysts were properly characterized by PXRD, SEM, TEM, DRS, Raman spectra. • The texture property and stability of T/G nanocomposites were investigated by BET and Zeta potential method. • Two carcinogenic MG and MB dyes were degraded via photocatalytic route under optimized conditions within very less time with good efficiency. Mineralization was also studied with COD analysis. • T/G nanocomposites (10 wt. % GO) exhibited improved photocatalytic activity in comparison to bare TiO 2 NPs. • Scavenger activity and recyclability study of catalytic material was performed. Titanium dioxide nanoparticles (TiO 2 NPs) and titanium dioxide-graphene oxide(T/G) nanocomposites were synthesized by easy and simple chemical routes and, characterized by using several analytical techniques such as Powder X-ray diffraction(P-XRD), Scanning electron microscope(SEM), Transmission electron microscopy(TEM), Thermo-gravimetric analysis(TGA), Brunauer-Emmet-Teller(BET), Raman analysis and UV-Vis-DRS spectrophotometer. The stability of nanomaterials was investigated by Zeta potential . The P-XRD revealed the formation of the anatase phase of TiO 2 NPs which favor photocatalytic activity. Both TiO 2 NPs and T/G nanocomposites have been investigated for the photocatalytic degradation of cationic dyes Malachite Green(MG) and Methylene Blue(MB) as model pollutants and degradation of 85 % and 93 % were observed in 13 and 60 minutes respectively, under visible light irradiation. These degradations followed pseudo second-order kinetics (PSO) with rate constant of 0.1291 and 0.1709 mol L −1 min −1 for MG and MB dyes respectively. The catalytic pathway seems to follow the generation of superoxide and hydroxyl radicals.