Experimental design study of RB 255 photocatalytic degradation under visible light using synthetic Ag/TiO2 nanoparticles: Optimization of experimental conditions

In the present study, silver-doped TiO2 (Ag/TiO2) nanoparticles were prepared by various Ag doping (wt%) and a combination of sol-gel and ultrasound irradiation. Ag/TiO2 nanoparticles were characterized by energy-dispersive X-ray analysis (EDX), scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. Based on the Taguchi method, photocatalytic degradation of (Reactive Blue 255) RB 255 azo dye was examined with Ag/TiO2 nanoparticles under visible light irradiation. Using this method, operation factors such as Ag doping (wt%), pH, mass of catalyst (g) and RB 255 concentration (ppm) were optimized successfully. The results showed that pH, compared to the other factors, plays an important role in the photocatalytic degradation of RB 255 azo dye. The isotherm study Weber-Van Vliet and Fritz-Schlunder (IV) models are the best descriptors of equilibrium behavior. In addition, the kinetic study results indicated that the pseudo first-order has a good agreement with the experimental data.