Optimization of Operating Parameters in Photocatalytic Activity of Visible Light Active Ag/TiO2 Nanoparticles

Reactive Blue 255 (RB 255) is a textile dye with global usage and is found in the wastewater of textile industries in large quantities. In the present study, silver-doped TiO2 (Ag/TiO2) nanoparticles with various Ag doping (wt %) were prepared by a combination of sol-gel and ultrasonication techniques. Ag/TiO2 nanoparticles were characterized by EDXA, SEM, TEM, and XRD methods. Based on the Taguchi method, photocatalytic degradation of RB 255 azo dye was investigated with Ag/TiO2 nanoparticles under visible light irradiation. By using this method, operation factors such as Ag doping (wt %), pH, catalyst load, and RB 255 concentration were optimized successfully. The results showed that pH, when compared to the other factors, plays an important role in the photocatalytic degradation of RB 255 azo dye. The isotherm study shows that Weber–Van Vliet and Fritz–Schlunder (IV) models are the best descriptors of equilibrium behavior. The experimental kinetic study results may be well described by a pseudo first-order model.