Effect of UV radiation and chitosan coating on the adsorption-photocatalytic activity of TiO2 particles.

The effect of chitosan, pH and UV-VIS radiation on the adsorption-photocatalytic properties of TiO2 dispersion was investigated on the basis of electrophoretic mobility, as well as spectrophotometric and dynamic light scattering measurements. For the degradation efficiency tests two different dyes: the cationic - methylene blue and the anionic - sunset yellow were used. The stability and photodegradation experiments were performed by varying the parameters: wavelength of light (range 450-750 nm), type and radiation time (UV and VIS; 0-5 h), pH (3 and 6) and pigment concentration (0.6 × 10-5-3.6 × 10-5 mol/dm3). In the chitosan-modified dispersions polysaccharide exhibits synergism of adsorption-photocatalytic properties of TiO2. Chitosan increases the biodegradability of the chitosan/TiO2 composite and additionally, it can be potentially used as a promising anti-microbial material.