The low temperature sol-gel approach is used in which the titanium butoxide (IV) precursor is hydrolyzed in the presence of acetic and nitric acids to form a bidentate acetate complex (1538, 1429 cm−1 IR doublet). It is known that the role of the acetic acid as a chemical modifier controls the condensation and oligomerization reactions, but other effect of the complex acetate ligand comprises the preferential crystallization of the titania into the anatase phase. In addition, it is found here, that the presence of such a ligand at acidic pH values considerably impacts the nanostructure i.e. the formation of smooth hydrophobic anatase films containing fine non-aggregated nano-crystallites with auto-assembled micro pores. The resulting anatase-acetate nano-crystalline material is used to form thin films by the flow coating process. 4.2 nm size crystalline anatase and fully dispersed nanoparticles form a pattern of ultra-small crystallites as shown by TEM that are presumably responsible for the remarkable smooth and macro porous thin films with applications in photo-catalysis.

Keywords: A. Peptization, B. Ultra-small anatase particles, A, Flow coating, A. Sol-gel stable anatase sol.