A comparison of TiO2 coated self-cleaning cotton by the sols from peptizing and hydrothermal routes

A homogeneous and stable titania precursor solution with highly crystallized TiO2 nanoparticles is necessary to form efficient coatings for photocatalytic self-cleaning cotton fabrics. By peptizing and hydrothermal methods, two kinds of precursor solutions and the corresponding coatings over cotton fabrics have been prepared. TEM, XRD, SEM, DRS and XRF have been applied to characterize the TiO2 nanoparticles and the coatings. Homogeneous and stable titania coatings with efficient photocatalytic activities formed over the cotton from both methods. TiO2 nanoparticles obtained from peptizing method were anatase nanocrystallites in the sizes of 3-5 nm with lots of defects. After hydrothermal treatment, the nanocrystallites further grew into 10-15 nm particles with twice enhanced crystallinity than the former one. Both coatings showed effective photocatalytic activity for MO degradation and stain removal, while the coating from the sol after hydrothermal treatment had a better performance.