Hybrid chitosan-TiO₂/ZnS prepared under mild conditions with visible-light driven photocatalytic activity

Thin films of chitosan (CS) coated on glass substrates were used as support for the immobilization of nanostructures TiO₂/ZnS via a mild chemical process followed by a hydrothermal treatment at 90 °C. The preparation route involved the coating of the CS film on the glass substrate followed by the deposition of a thin layer of Ti(OBu)₄ precursor and immersion in a solution of Zn(O₂CCH₃)₂ and Na₂S. After a hydrothermal treatment at 90 °C, an even layer of TiO₂ anatase decorated by ZnS nanorods was generated. Evidence of the formation of TiO₂ anatase and ZnS was confirmed by XRD, Raman and XPS, and the morphology of the TiO₂ layer and ZnS nanoparticles was analyzed by FE-SEM observations. The photocatalytic activity of the CS-TiO₂-ZnS systems was evaluated by the degradation of a wide range of organic compounds including aromatic amines and carboxylic acids under a conventional halogen lamp.