Synthesis of hollow CdS-TiO₂ microspheres with enhanced visible-light photocatalytic activity

CdS-TiO₂ composite photocatalyst in the shape of hollow microsphere was successfully synthesized via the hard-template preparation with polystyrene microspheres followed by ion-exchange approach. The hollow CdS-TiO₂ microspheres significantly extended the light adsorption into visible light region, comparing to TiO₂ microspheres. It led to much higher photocatalytic activities of hollow CdS-TiO₂ microspheres than that of TiO₂ during the photodegradation of rhodamine B under visible light irradiations. Furthermore, the well-remained hollow structure could achieve light multireflection within the interior cavities and the separation of photo-induced electrons and holes is efficient in CdS-TiO ₂, which were facilitated to improving the photoactivity.