CdS quantum dots encapsulated within the mesopores of MCM-41 and interlayers of montmorillonite as photocatalysts for rhodamine-B degradation in aqueous solution.

Capping agent-free CdS quantum dots (CdS-QDs) were synthesized within the mesopores of MCM-41 and interlayers of montmorillonite (MMT), using a safe manner by a facile ion exchange-precipitation protocol. The mesopores of MCM-41 and interlayers of MMT controlled the growth of CdS-QDs. The obtained CdS-QDs@MCM-41 and CdS-QDs/MMT were characterized by X-ray diffraction (XRD) analysis, energy-dispersive X-ray (EDX), diffuse reflectance UV-Vis, and photoluminescence spectroscopies. Photodegradation of rhodamine-B (RhB) over these embedded CdS-QDs was investigated under UV-Vis light irradiation. The influences of some parameters on the photodegradation of RhB such as pH, temperature, and UV-Vis irradiation time were investigated. The results showed that the CdS-QDs/MMT and CdS-QDs@MCM-41 have high efficiencies for RhB photodegradation under UV-Vis illumination.