Synthesis, Characterization and Applications of GO–TiO2 Nanocomposites in Textile Dye Remediation

Textile azo dyes are used for coloring fabrics which are found to be potentially carcinogenic and mutagenic chemicals. It is disposed of as industrial effluents, causing major hazardous impacts on the aquatic ecosystem and getting deposited onto the soil for a prolonged period. Several conventional methods have been previously applied to eliminate these dyes but had low efficiency and high cost limitations. In order to overcome those issues, in this study, we have synthesized a GO–TiO2 nanocomposite using the solvothermal method from graphene oxide (GO) nanoparticles and titanium dioxide (TiO2) nanoparticles which were synthesized individually using modified Hummer’s method and sol–gel method, respectively. The prepared TiO2 nanoparticles and GO–TiO2 nanocomposite were characterized using UV–visible spectrophotometry, FTIR spectroscopy, dynamic light scattering, zeta potential, XRD, scanning electron microscopy, and EDAX analysis. The textile azo dyes used were Crystal Violet, Brilliant Green, Malachite Green, and Rhodamine B, and their photocatalytic degradation was observed spectrophotometrically using TiO2 nanoparticles and GO–TiO2 nanocomposite. From the results obtained, we found that the GO–TiO2 nanocomposite was successfully synthesized with TiO2 doping and effectively reduced all the dyes used in this study compared to the standard photocatalyst TiO2. On the other hand, the Brilliant Green and Malachite green have shown an increase in their color after TiO2 treatment, which was diminished by using GO–TiO2 nanocomposites. The biocompatibility of this GO–TiO2 was studied using zebrafish embryos and the results demonstrated that the GO–TiO2 nanocomposite was safe for the embryos without causing any delay in hatching or developmental abnormality. The outcome of this study yields a novel application of GO–TiO2 nanocomposite in the reduction in azo dyes showing potential applications in wastewater remediation. Further studies are required to test the biocompatibility and efficacy of other dye removals.