Sunlight-Induced Photocatalytic Removal of Paracetamol Using Au-TiO₂ Nanoparticles

Using sunlight as the driving force for photocatalytic processes holds great promise for sustainability. As a starting point for developing a material capable of degrading aquatic pollutants using solar energy as a stimulus, this work focuses on synthesizing Au-TiO₂ nanocomposites using the deposition-precipitation method. Characterization of Au-TiO₂ nanoparticles was performed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Transmission Electron Microscopy (TEM). A model pollutant, paracetamol, was used to test the synergetic effect of Au (0.05 wt%) nanoparticles (NPs) with TiO₂ on photocatalytic activity. The influence of the parameters pH, loading (0.4, 0.8, and 1 g/L), pollutant concentration (20, 30, 40 ppm), and contact time (30, 60, 90, 120, 150, and 180 min) was studied by exposing the NPs to solar radiation. The photocatalytic degradation was most effective at a contact time of 3 h, an initial concentration of 20 ppm, and a pH of 6.8. Under these conditions, paracetamol in 1 g/L of Au-TiO₂ nanocomposites can be degraded by more than 99.17% under solar irradiation. As a result of the Au-TiO₂ composite's ability to successfully serve as a photocatalyst using sun radiation, water purification processes can be more widespread, cost-effective, and environmentally friendly.