Design and synthesis of Hollow Sea-urchin-like TiO2@CdS Photocatalysts for visible-light-driven degradation of antibiotics in wastewater

To enhance the visible-light catalytic activity and broaden the light absorption range of TiO 2 , a series of three-dimensional hollow sea-urchin-like TiO 2 @CdS composite photocatalysts were synthesized via a one-step hydrothermal method. The microstructure and photoelectrochemical properties of the synthesized TiO 2 @CdS composites were systematically characterized by multiple techniques. The scanning electron microscopy results showed that the pure TiO 2 present the hollow sea-urchin-like structure and the overall morphology of the TiO 2 @CdS composite material is hardly changed. PL results showed that the introduction of CdS quantum dots to TiO 2 matrix to form a heterojunction can effectively improve its photoelectron transfer efficiency and enhance electron-hole separation. The UV–vis results indicated that the introduction of CdS QDs significantly enhanced the visible-light absorption of TiO 2 . The performance for the visible-light-driven degradation of tetracycline hydrochloride (TCH) was systematically investigated. The results showed that the TCH degradation efficiency reached 83.71 % within 1 h of visible-light irradiation and further improved to 93.59 % after 3 h. Moreover, the degradation rate was markedly accelerated under alkaline conditions and the degradation rate can reach 96.82 %. After five consecutive cycles, the TiO 2 @CdS composites exhibited negligible loss in photocatalytic activity, confirming their excellent visible-light catalytic degradation performance and outstanding reusability.