Visible Light-Driven Photocatalytic Degradation of Organic Dyes using Graphene Oxide and Titanium Dioxide (TiO2-GO) Heterojunction

Water is the main source required for the survival of humans, animals and plants that has been contaminated by humans with various and dangerous pollutants such as dyes. This study focuses on the photocatalytic method for the purification of wastewater containing dyes. The TiO₂ photocatalyst was modified with graphene oxide (GO) nanoparticles to examine their properties and evaluates their photocatalytic activity. The crystalline, physicochemical, and photocatalytic properties of the synthesized samples were measured using different analyses like XRD, FT-IR, SEM, EDS-MAP, DLS, UV–Vis DRS and PL. The synthesized photocatalysts were analyzed for the photocatalytic elimination of crystal violet cationic dye under visible irradiation. The outcome indicated that the bandgap of titanium dioxide decreased from 3.2 eV to 2.79 eV after composite formation with graphene oxide, which is capable of degrading the dye in the visible light region. The TiO₂/GO nanocomposite showed a 96% performance in the degradation of crystal violet dye in optimal conditions, including a pH of 8, a photocatalyst dosage of 0.02 g, a primary dye concentration of 10 ppm, and a reaction time of 90 min. In addition, it was shown that hydroxyl and superoxide radicals play the main roles and have the primary effect in degradation.