Titania and Noble Metals Deposited Titania Catalysts in the Photodegradation of Tartazine

Nanoparticles of TiO2 were synthesised by sol-gel technique and photo deposition of about 1% noble metal (M/TiO2, M = Ag, Au, and Pt) on TiO2 was carried out. The catalysts were characterised by XRD, TEM, BET, FT-IR, and UV-Visible spectroscopy. Using commercial TiO2 (P-25 Degussa), the conditions such as dye concentration, catalyst weight and pH were optimized for complete decolourisation of textile dye tartazine (TAZ) under UV and visible irradiations. Among the catalysts tested, the synthesised TiO2 showed better photocatalytic activity than TiO2 (P-25 Degussa). Whereas, M/TiO2 catalysts showed remarkable photocatalytic activity towards the decolourisation of TAZ even under visible irradiation. This enhanced activity of M/TiO2 catalyst may be attributed to the trapping of conduction band electrons by noble metals.