Reactive Dye Removal by Photocatalysis and Sonophotocatalysis Processes Using Ag/TiO2/Fe3O4 Nanocomposite

Abstract

In this study, the removal efficiency of reactive red 195 (RR195) dye by photocatalysis process under UV-A and visible irradiation using Ag/TiO₂ and Ag/TiO₂/Fe₃O₄ nanocomposite was investigated. The structural properties of the photocatalyst were evaluated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope-energy dispersive X-ray (SEM–EDX), and transmission electron microscope (TEM) analyses. The effects of irradiation time, initial dye concentration, light power, solution initial pH, and ultrasound application on RR195 removal by photocatalysis process were determined experimentally. Ninety-two and 95% dye removal efficiencies were obtained using Ag/TiO₂/Fe₃O₄ photocatalyst, after 30 min of UV-A irradiation for photocatalysis and sonophotocatalysis processes, respectively. The removal of RR195 dye under visible irradiation for 120 min using magnetic nanocomposite was determined as 92% and 96% for photocatalysis and sonophotocatalysis processes, respectively. The percentage of RR195 removal under UV-A and visible light decreased with the increase in initial dye concentration and pH values and increased with the increase in light power. In photocatalysis experiments, the highest dye removal was obtained as 98% and 96% for 120 min visible irradiation and 30 min UV-A irradiation, respectively, under optimum initial conditions (pH: 3, Ag/TiO₂/Fe₃O₄ dose: 0.1 g/L, dye concentration: 25 mg/L, and light power: 27 W).