TiO2 nanoparticles and TiO2/CS nanocomposites have been synthesized using the sol-gel method. Characterization by XRD, FTIR, and UV-vis was carried out to determine the structure, size, functional groups, and energy band gap of the synthesized samples. Moreover, the methyl orange (MO) degradation capability of nanoparticles and nanocomposites under ultraviolet light was studied, and the results are described in detail.