Preparation and photocatalytic performance of CdS@Bi2WO6 hybrid nanocrystals

Abstract The hybrid nanocrystals of cadmium sulfide (CdS) and bismuth tungstate (Bi2WO6) (CdS@Bi2WO6) were well-prepared in the nanoreactors of Bi2WO6-contained sodium polyacrylate (PAANa) latex particles, by means of cadmium sulfate/sodium sulfide (CdSO4/Na2S) solutions absorption and solvothermal treatment. The influences of CdSO4/Na2S millimolar ratio on structure and photocatalytic performance of hybrid nanocrystals were investigated. With 3:1 of Cd2+/S2- millimolar ratio in feeding, CdS nanorods on the surface of Bi2WO6 cluster were obtained and its length increased after solvothermal treating; the resultant CdS@Bi2WO6 degraded 96.1% of RhB after illuminating for 120 minutes, which was more effective than others. With the 1:2 or 1:3 of Cd2+/S2- millimolar ratio, the solvothermal treated cubic-CdS were agglomerated to cluster which attached on the surface of Bi2WO6 cluster, and the agglomerates size increased accordingly. The photocatalytic mechanism suggests that the superoxide ions and holes were the active species produced by CdS@Bi2WO6 in the photocatalytic process. The grown CdS nanorods on the surface of Bi2WO6 had better charge separation ability than the grown CdS clusters on the surface of Bi2WO6. The CdS@Bi2WO6 hybrid nanocrystal with the definite-designed structure will possess the excellent photocatalytic performance.