Photoactive TiO2 films on cellulose fibres: synthesis and characterization

The preparation of photoactive fibres has been successfully developed by depositing and grafting TiO2 nanoparticles on cellulose fibres by using a sol–gel method at low temperature (∼100 °C)—designed for practical applications. The original and treated fibres have been characterized by several techniques (SEM, HRTEM, FTIR, Raman, UV–vis spectroscopy, XRD, and TGA). The TiO2 nanoparticles, 3–5 nm in size, have been found to form a homogeneous thin film on the fibre surface, which shows efficient photocatalytic properties when exposed to solar-like light. The photocatalytic activity, tested by measuring the degradation of adsorbed methylene blue (MB) and of a heptane-extracted bitumen fraction (BF) containing a mixture of heavy aromatic hydrocarbons, is fully maintained upon several numbers of impregnation–photodegradation cycles. The fibre structure is not altered upon light exposure. The TiO2 film is firmly anchored and the photocatalytic activity is retained even after 20 washing cycles. This preparation technique can be also applied to new fabrics to create self-cleaning and UV irradiation protection properties in them.