Photocatalytic and antimicrobial activities of chitosan-TiO₂ nanocomposite

Chitosan, a natural polysaccharide widely used for various biological applications due to their potential benefits. Incorporation of biomaterials with semiconductor has been exploited for waste water treatment and biological applications due to their nanometric sizes and biocompatibility of chitosan. Chitosan-Titanium dioxide (CS-TiO₂) nanocomposite was synthesized and their optical, structural, spectral, thermal, morphological and elemental analyses were carried out by several techniques. The particle size of the synthesized CS-TiO₂ nanocomposite was around 90nm and has a crystalline structure with anatase phase of TiO₂. The prepared nanocomposite acts as a photocatalyst for the removal of rhodamine B (RhB) and congo red (CR) dyes under visible light irradiation. The pseudo first order kinetics was derived according to Langmuir-Hinshelwood (L-H) model. The nanocomposite also proved to be an excellent antimicrobial agent against Gram-positive and Gram-negative bacteria; and also show activity against fungus. The antimicrobial activity of the CS-TiO₂ nanocomposites exhibits a zone of inhibition ranged between 10.333±0.5773 and 25.667±1.5275 (mm).