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

Abstract

Titanium dioxide nanoparticles (TiO2 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 TiO2 NPs which favor photocatalytic activity. Both TiO2NPs 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 min, 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.