Photocatalytic-oxidation of solid state chitosan by immobilized bilayer assembly of TiO2–chitosan under a compact household fluorescent lamp irradiation

Photocatalytic-oxidation of an immobilized solid state chitosan (CS) by assembling a bilayer TiO2–CS-glass system in aqueous solution under 45-W compact household fluorescent lamp was investigated. The structural and optical changes of CS were characterized by elemental analysis, Fourier-transform infrared spectroscopy (FT-IR) analysis, UV–vis diffuse reflectance spectroscopy (DRS) analysis and photoluminescence spectroscopy (PLS) analysis. The results indicated the formation of carbonyl side group and elimination of some amino group without altering much of the whole structure of CS. Furthermore, the photocatalytic-oxidation process led to the formation of an irregular surface morphology of CS according to the SEM images. The visual color changed to a more intense brown and less water uptake was also observed. The experimental results show that the bilayer TiO2–CS-glass arrangement system can be considered as a convenient and environmentally friendly method for green chemistry application, especially in the field of the mild oxidation of a solid state CS.