Photocatalytic degradation of C.I. Acid Orange 7 by TiO₂ nanoparticles immobilized onto/into chitosan‐based hydrogel

Photocatalytic degradation of dye C.I. Acid Orange 7 in aqueous solution using TiO₂/hydrogel nanocomposite under solar light simulating source was studied. Hydrogel based on chitosan, itaconic and methacrylic acid was modified with colloidal TiO₂ nanoparticles synthetized by acidic hydrolysis of TiCl₄ and commercial Degussa P25 TiO₂ nanoparticles. SEM/EDX analysis confirmed the presence of TiO₂ nanoparticles onto/into hydrogel. It was found that both types of photocatalysts efficiently removed the dye from solution, but sorption rates and photodegradation efficiency were higher in the case of colloidal TiO₂ nanoparticles. They ensured complete discoloration of dye solution. The efficiency of the reused TiO₂/hydrogel nanocomposite showed that photodegradation activity was maintained at satisfactory level after three repeated cycles of illumination. POLYM. COMPOS., 35:806–815, 2014. © 2013 Society of Plastics Engineers