Synthesis of high quality TiO2 membranes on alumina supports and their photocatalytic activity

This study describes the synthesis of TiO2 membranes on alumina supports by the spin-coating technique using the sol-gel method with water-soluble chitosan (WSC) as an additive. After calcining the sample at 500 °C, the WSC was completely decomposed, and the remaining membrane consisted mainly of anatase. Controlling the amount of WSC in the TiO2 sol to within a range of 0.1 wt.%-0.3 wt.% resulted in TiO2 membranes on alumina supports with enhanced structural and catalytic properties. These properties included a high surface area (164 m2/g-116 m2/g) and porosity (47.3%-52.2%), homogeneity without cracks and pinholes, thinness (0.8 μm), as well as high degradation of methyl orange (61.2%-49.2%).