Removal of ibuprofen using a SiO2@xTiO2 photocatalyst under UV irradiation

This paper reports on the photodegradation of ibuprofen (IBP), as a model pharmaceutical, using SiO 2 @xTiO 2 synthesized via a hydrothermal method. The catalysts were prepared by adding TiO 2 at different weight loadings (2, 5, 10 and 20 wt%) to a Stober synthesized silica (ca. 120 ± 10 nm diameter). The core–shell materials were characterized by TEM, XRD, reflectance diffuse spectroscopy, Raman spectroscopy, BET analysis and electrical conductivity. The photodegradation was performed using UV irradiation (254 nm, 25 W). The effect of catalyst dosage and the pH of the solution on the rate of IBP photodegradation was investigated. The SiO 2 @xTiO 2 showed excellent photodegradation efficiency and the decomposition reaction was found to be pseudo first order where the degradation rate of IBP increased with the formation of H 2 O 2 . Optimal experimental conditions gave 99% IBP degradation with the SiO 2 @20TiO 2 catalyst (0.1 g/L, at 180 min of irradiation).