Fabrication and characterization of SiO2@TiO2@silicalite-1 catalyst and its application for degradation of rhodamine B

Abstract

SiO₂@TiO₂@silicalite-1 catalyst, with TiO₂ (Degussa P25) nanoparticles encapsulated by SiO₂ and adhered on the surface of silicalite-1 zeolite, was successfully fabricated by combining pressing, sintering and infiltration methods. The samples were characterized by XRD, SEM, FT-IR, TEM, nitrogen sorption, and UV-vis diffuse reflectance spectra. The photocatalytic properties were investigated by degradation of rhodamine B (RhB) aqueous solution under UV light. The results show that TiO₂ nanoparticles are coated with a SiO₂ shell and bonded together. The core/shell structure of TiO₂@SiO₂ is attached to the surface of silicalite-1 particles. The photocatalytic efficiency of TiO₂@silicalite-1 is 97.4%. When the catalyst is coated with SiO₂, its photocatalytic efficiency is significantly improved to 99.7%. Furthermore, the rate of degradation using SiO₂@TiO₂@silicalite-1 is 1.54 times faster than that using TiO₂@silicalite-1.