Study of photocatalytic activities of nanoscaled metal oxides on textiles

A systematic study of the synthesis and application of nanoscaled metal oxides with photocatalytic activity was conducted. The synthesis was based on sol-gel nanotechnology at low temperatures and atmospheric pressure. The metal oxide sols were then applied to textile materials to form self-cleaning films by a dip-pad-dry-cure process. The main research work was focused on the synthesis, characterization, and application of pure anatase titanium dioxide (TiO2) and anatase TiO2 doped with other materials.;Nanocrystalline anatase TiO2 sols were prepared by an aqueous sol-gel process at low temperatures. These TiO2 treated cotton fabrics possess significant self-cleaning properties, such as bactericidal activity, colorant decomposition and degradation of red wine and coffee stains. The mechanical properties and durability of TiO2 treated cotton fabrics were investigated.;Anatase TiO2 prepared by an aqueous sol-gel process at 60°C was applied to polyester fabric that was pretreated with low temperature plasma. The wettability of polyester towards the titania sol and the adhesion of titania layers to polyester fibres were improved. The self-cleaning properties of the anatase functionalized polyester fibers were studied.;To improve the photocatalytic activity of TiO2, anatase TiO 2/SiO2 nanocomposites were developed by an aqueous sol-gel process at a low temperature. The morphology characterization of these nanocomposites showed that TiO2 nanoparticles were deposited on the surface of SiO2 spheres. The nanocomposites treated cotton fabrics demonstrated higher photocatalytic activity in comparison to pure TiO2 treated cotton fabrics.;To eliminate the need for high temperature operations and the use of corrosive chemicals in synthesizing anatase TiO2, a new synthesis method for anatase TiO2 was developed using an aqueous sol-gel process followed by aging at room temperature. This study further optimizes the synthesis conditions for anatase TiO2 which could contribute to the large scale fabrication of self-cleaning textiles.;To extend the absorption of TiO2 into visible region and to reduce electron-hole recombination to further improve photocatalytic activity of TiO2, Fe3+ doped TiO2 was synthesized by an aqueous sol-gel process at 60°C with the addition of Fe3+ dopant. Higher photocatalytic activity was achieved at optimum doping level compared to that of the pure TiO2.