Electrospun CuS nanoparticles/chitosan nanofiber composites for visible and near-infrared light-driven catalytic degradation of antibiotic pollutants

In the present study, copper sulfide nanoparticles (CuS NPs)/chitosan nanofiber composites with photo-Fenton catalytic and photothermal activities were developed to enhance the removal of recalcitrant biomedical pollutants such as tetracycline (TC). CuS NPs were encapsulated in CS nanofibers by an electrospinning technique (CS ENFs) to obtain CuS@CS ENF composite (CuS@CS ENFC) membranes with high porosity and large surface areas. An investigation of the mechanism of TC removal revealed the complementary performances between adsorption of TC by CS ENFs and the Fenton-like reaction of TC with CuS NPs during the degradation of TC. The ENFCs were cross-linked with genipin (GP) to improve the stability of CuS NPs in long-term storage and the availability of the ENFCs over a wide pH range. CuS@CS ENFCs generated electron-hole pairs and local hyperthermia under near infrared (NIR) laser irradiation, which caused the H₂O₂-involved catalytic reaction on ENFCs to take place at a faster rate than in the dark. Compared to pristine CuS NPs, ENFCs were more easily separated from the reaction mixture, and the adsorption sites on ENFCs could be regenerated by the photo-Fenton catalytic degradation of TC. The ENFCs also exhibited antibacterial activity. ENFCs are eco-friendly and easily recyclable, so they have the potential for chemical engineering, biomedical, and environmental applications.