Synergistic photocatalytic removal of organic pollutants in the aqueous medium using TiO2–Co3O4 decorated graphene oxide nanocomposite

Organic pollutants generated from different industrial sources cause soil and water pollutions, which creates an ecological imbalance. Metal oxide and carbon-based nanocomposites are extensively used to remediate industrial pollution. In this study, TiO2–Co3O4 and TiO2–Co3O4/graphene oxide nanocomposites were prepared and utilized to degrade the organic pollutants such as crystal violet, methylene blue and ofloxacin. The structural, optical and morphological properties of the nanocomposites were confirmed by XRD, FTIR, UV–Vis, FE-SEM, TEM and BET analysis. The XRD and SAED pattern of the nanocomposites confirms the formation of titanium dioxide-cobalt oxide with graphene oxide. The broadening of the hydroxyl group (3556 and 1638 cm−1) and metal oxide band was observed from the FTIR spectra after the incorporation of cobalt oxide and graphene oxide. The EDX spectra confirm the occurrence of Ti, Co, and O peaks in TiO2–Co3O4 (TC), whereas GO-TiO2–Co3O4 (GTC) nanocomposites reveal the occurrence of C, Ti, Co, and O. In the dark condition, the prepared catalyst shows less than 10% of organic pollutant removal. Under light irradiation, GTC catalysts completely degraded the MB, CV and OFX, whereas TC showed 62%, 54%, and 31%, respectively. The enhancement in the photocatalytic removal of organic molecules is due to the decreased particle size, surface area and bandgap of GTC. The photocatalytic behaviour of GTC is significantly higher than the TC, thus it concluded that GTC has the higher efficiency towards the removal of organic pollutants present in the aqueous medium.