Mesoporous silica nanospheres decorated with CdS nanocrystals for enhanced photocatalytic and excellent antibacterial activities.

Uniform SiO2@CdS mesoporous nanospheres with an average diameter of 300 nm have been synthesized successfully by a facile process. The as-prepared mesoporous composite nanospheres have a BET-specific surface area of 640 m(2) g(-1) and an average pore size of 2.82 nm. The results demonstrated that more than 60% Rhodamine B (RhB) dye in solution (4.8 mg L(-1), 50 mL) could be removed by adsorption in the dark for 30 min using the as-prepared SiO2@CdS mesoporous nanospheres (40 mg). The as-prepared SiO2@CdS mesoporous nanospheres have a mesoporous nanostructure, suggesting a higher specific surface area and resulting in a strong adsorption ability. In addition, the mesoporous silica was decorated with ca. 5 nm CdS nanocrystals, which showed excellent photocatalytic activity under visible light and could rapidly remove most of the RhB molecules from a pollutant solution under visible light irradiation. Furthermore, the mesoporous SiO2@CdS nanospheres synthesized by the present protocol exhibited excellent antibacterial activity.