The room temperature in-situ sol gel technique was used to synthesize TiO2 supported chitosan (CS) nanocomposites. The effect of calcination was assessed in the context of its physicochemical and adsorption-photodecolorization properties. During sol gel, hydrolysis and condensation of titanium alkoxide was conducted under acidic conditions, which resulted in the formation of crystalline anatase phase in TiO2-CS (TC) composite at room temperature. Furthermore, calcination treatments (100 degrees C, 300 degrees C, 500 degrees C) gradually increased the charge carrier recombination rates, due to the thermal degradation of Chitosan. Photocatalytic activity was assessed using Methyl orange, which resulted in 100% decolorization within 90 min of UV exposure with un-calcined nanocomposite. Hence, the reactive OH and NH2 functional groups on the surface of CS are responsible for the adsorption-photo decolorization process. Overall, this study provides comprehensive data on the effective modification of TiO2 with Chitosan and the effect of calcination on the physicochemical and adsorption-photo decolorization properties of the TC nanocomposite. (C) 2016 Elsevier Ltd. All rights reserved.