Sorption of titanium complexes with organic acids on titanium (IV) oxide

Nanocrystalline titanium dioxide, due to its efficiency, low cost, non-toxicity, photo- and thermal stability, is the most studied semiconductor oxide material that has found application in Grätzel solar cells, as a component of ceramic, composite, catalytic, and sorption materials. The effectiveness of nanocrystalline titanium dioxide is determined by many factors, many of which are controlled by the nanotechnology methods: particle size, crystallinity, phase composition, morphology, and surface composition. The problem for the researchers is to track, study, understand and, in the limit, turn each of these parameters into a manipulated control tool. In the present study we consider the sorption of three different organic complexes on a related phase, namely, titanium oxide in the form of nanoparticles. The sorption of complexes is considered as controlled growth of the oxide phase and can be used in the future as a method for surface modification. A method for the preparation of two complexes of titanium with organic acids is described, one of which is a complex with phenylglycolic acid, obtained for the first time. A comparison of physicochemical parameters of the sorption of organic titanium complexes has shown that the absolute values of Gibbs free energy of the complexes sorption are rather low. It has also been shown that the complex with citric acid has the highest affinity, while the presence of an aromatic component in an organic acid almost doubles the limiting concentration of the complex on the sorbent surface.