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

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.