Tailoring the activity of Ti-based photocatalysts by playing with surface morphology and silver doping

TiO2 thin films have been prepared on cotton fibres by using sol–gel method at low temperature (∼100 °C) and metallic Ag nanoparticles were deposited on porous TiO2 film by photoreduction. The Ag–TiO2 covered cotton fibres show multichromic behaviour under visible and UV light exposure as well as photoactivity [M.J. Uddin, F. Cesano, F. Bonino, S. Bordiga, G. Spoto, D. Scarano, A. Zecchina, J. Photochem. Photobiol. A: Chem., 89 (2007) 286-294]. The developed multiactive cotton fibres show grey colour under visible light and change their colour reversibly to deep brown upon ultraviolet light exposure. The original and treated fibres have been characterized by several techniques (SEM, AFM, EDS microanalysis, Raman, UV–vis spectroscopy, XRD and TGA) and the Ag–TiO2 nanoparticles have been found to form an homogeneous thin film on the fibre surface.