Effective visible-light-driven photocatalytic degradation of 17Α-ethynylestradiol by crosslinked CdS nano-rod/TiO2 (B) nano-belt composite

New CdS nano-rod/TiO2 (B) nano-belt composites (denoted as CdS-NR/TiO2 (B)-NB) were successfully prepared via a two-step hydrothermal process. The chemical composition and structure of synthesized materials were characterized by X-ray diffraction (XRD), field emission scanning microscopy (FESEM), transmission electron microscopy (TEM), element map, UV visible diffuse reflectance spectroscopy (UV–vis DRS) and photoluminescence spectroscopy (PL). The prepared samples were used to remove 17α-ethynylestradiol (EE2) under visible light irradiation, which has most potent estrogenic activity and resists to biodegradation. The results show that the B-type TiO2 (TiO2(B)) nano-belts are crosslinked with CdS nano-rods to form heterojunction with higher removal rate (92.00%) than pure CdS nanorods (55.67%) for 3 mg/L EE2 within 120 min when the mass ratio of CdS nanorods to TiO2 (B) nanobelts is 1:15. The degradation rate constant of EE2 over CdS-NR/TiO2 (B)-NB (0.001763 min−1) is 3 times higher than pure CdS-NR (0.00567 min−1) under visible light irradiation. Charge generation, migration and possible photocatalytic mechanism of EE2 on CdS-NR/TiO2 (B)-NB photocatalyst has been proposed based on the theoretical calculation and reactive species trapping experimental results.