The photografted PET fabrics with MAPTMS immersed in aqueous titanium (IV) isopropoxide (TTIP) solution was gelled under acidic condition via hydrolysis and condensation reactions, which produce a nano coating of TiO_2$ on the PET fabrics less than a diameter of 200nm. With increase in gellation time, nano $TiO_2$-coated fabrics showed decreased reflectance at the visible region particularly at 440 nm. Also $TiO_2$-containing fabrics became more susceptible to thermal degradation above $470^{circ}C$. The PET fabrics containing $TiO_2$ nanoparticles showed better photocatalytic properties such as the photobleaching of methylene blue and ammonia deodorization in comparison with the untreated and grafted PET fabrics. The UV-induced degradation occurred during photobleaching of methylene blue solution, which was more pronounced in the ases of grafted and nano-coated samples.