Effect of Cation Exchange Time on The Morphology and Photoactivity of CdS/Ag2S Composites for Ciprofloxacin Degradation
Authors: Ngoc Bao Tri Pham, Vinh Quang Dang, Kim Ngoc Pham, Cheng-Kuo Tsai, Thanh Tam Nguyen, Cong Khanh Tran
Abstract:
The effect of reaction time in the cationic exchange method on the CdS/Ag2S structure and photocatalytic activity is investigated in this study. A hydrothermal approach is used to produce CdS nanorods (NRs), and then a cation exchange method is applied to synthesize CdS/Ag2S composites. The heterostructure between CdS and Ag2S is determined by the X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies. Comparing pure CdS NRs and CdS/Ag2S by the UV-Vis diffuse reflection spectra (DRS) data, the introduction of Ag2S is proven to enhance the light absorption in visible region. The Brunauer–Emmett–Teller method indicates that CdS and CdS/Ag2S are mesopore materials and the specific surface areas (SBET) of CdS, CdS/Ag2S-15, CdS/Ag2S-30, and CdS/Ag2S-60 samples without and with a cation-exchange reaction time of 15, 30, and 60 min are 305, 900, 187, and 52 m2·g-1, respectively. The photocatalytic activity of CdS/Ag2S is examined through the ciprofloxacin photodegradation. The ciprofloxacin degradation rate increases with the introduction of CdS and reached a maximum value of 60% within 180 min for CdS/Ag2S-15 under simulated sunlight irradiation, which is 1.5 times greater than that of pure CdS. The ciprofloxacin degradation rate decreases as the cation-exchange reaction time is increased to 60 min (26% after 180 min illumination).
Keywords: CdS/Ag2S, cation exchange reaction, photocatalysis, ciprofloxacin degradation
Link: https://onlinelibrary.wiley.com/doi/abs/10.1002/pssa.202100634
