Titania coated silica nanocomposite prepared via encapsulation method for the degradation of Safranin-O dye from aqueous solution: Optimization using statistical design

Titania coated silica nanoparticles, which were synthesized via nanoparticle encapsulation route, are employed to degrade safranin-O dye from aqueous solution under UV light irradiation and were characterized by FT-IR, XRD, FESEM, N2 adsorption-desorption method and Zeta potential measurement. The results showed that the nanoparticles have a core-shell structure composed of about 100 nm of diameter of silica with several TiO2 fine particles in shell. After the degradation, this process is optimized through the response surface methodology (RSM). In this response study, photodegradation efficiency was evaluated by three main independent parameters such as catalyst dose, initial dye concentration and reaction time. Parameter sensitivity studies of the degradation efficiency of titania coated silica nanoparticles have shown 93.29% degraded under the optimal conditions of catalyst dose of 89.80 mg/g, initial dye concentration of 17.61 mg/L and reaction time of 12 min. We cross-checked the predicted values of degradation efficiency with the experimental values and were found to be in good agreement (R2=0.9983 and adj-R2=0.9967). Keywords: TiO2 coated silica nanoparticles, Photodegradation, Safranin O, Response surface methodology, Central composite design