This study describes the synthesis of TiO2 membranes on alumina supports by the spin-coating technique using the sot-gel method with water-soluble chitosan (WSC) as an additive. After calcining the sample at 500 degrees 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 m(2)/g-116 m(2)/g) and porosity (47.3%-52.2%), homogeneity without cracks and pinholes, thinness (0.8 mu m), as well as high degradation of methyl orange (61.2%-49.2%). (C) 2011 Elsevier B.V. All rights reserved.