Photocatalytic performance assessment of GO and Ag co-synthesized TiO2 nanocomposite for the removal of methyl orange dye under solar irradiation

Abstract

Abstract Recently, the visible-light-driven titanium dioxide (TiO2) photocatalytic process has received greater attention in the treatment of organic pollutants because of its less energy consumption, higher performance, and sustainable nature. In this context, the present study was conducted to synthesize nanocomposites of TiO2 photocatalyst by doping with graphene oxide (GO) and silver (Ag) nanoparticles using sol–gel along with solvent heat treatment method. The physic-chemical properties of all photocatalysts were characterized by XRD, SEM, FTIR, and UV–Vis/DRS​ spectrophotometer analyses. The XRD showed the increased amount of anatase phase of TiO2/GO/Ag crystal structure compared to undoped TiO2, and TiO2/GO nanocomposite. More rugged and roughness surface was observed for TiO2/GO/Ag as compared to undoped TiO2, and TiO2/GO from SEM images. FTIR confirms the stretching vibration of the hydroxyl group in TiO2 lattice structure. Under solar irradiation with 3 h contact time at a fixed pH of 6.8, all the photocatalysts showed effective removal of 15 mg L−1 methyl orange (MO) dye in aqueous solution and the removals were 72.53%, 86.20%, and 97.66% for undoped TiO2, TiO2/GO, and TiO2/GO/Ag nanocomposites, respectively, at the same dose of a photocatalyst. The photocatalytic performances of all the catalysts were decreased with the increase of dye concentration and increased with the addition of oxidant H 2 O2. The kinetic study indicates that the photocatalytic degradation of MO dye was time-dependent and was fitted the best with experimental data. Based on the experimental results, it can be concluded that the synthesized TiO2/GO/Ag nanocomposite has great potential for sustainable management of textile wastewater.