DEGRADATION OF DYE BY TiO2 NANOPARTICLES

Present work shows the comparative study of bare and metal loaded TiO2 nanoparticles of different phase (anatase and rutile) for the photodegradation of methylene blue dye under visible light irradiation. Anatase TiO2 nanoparticles were prepared by sol gel method and rutile TiO2 nanoparticles were prepared by calcining P25TiO2 at 800 0 C for 2 hours in a muffle furnace. Different weight percent (0.21 wt%) of silver metal were loaded over the prepared TiO2 catalyst by wet impregnation-reduction method. The Photodegradation of methylene blue dye (20 mL, 0.01 mM) was carried out by using TiO2 nanoparticles (20 mg) and metal loaded TiO2 nanoparticles under visible light irradiation. Bare anatase TiO2 was found to be inactive for the photodegradation of dye under the visible light. However, silver loaded anatase TiO2 nanoparticles degraded methylene blue dye under the visible light efficiently. 0.5 wt% silver loaded anatase TiO2 degraded the dye within 45 minutes. Bare rutile TiO2 also found to be almost inactive for methylene blue degradation under visible light irradiation. However, 0.5 wt% silver loaded rutile TiO2 degraded the dye within 25 minutes. Interestingly 0.5 wt% silver loaded rutile degraded the dye in just 5 minutes under sunlight irradiation. The results show that the silver metal loaded rutile TiO2 nanoparticles are more active for the dye degradation under visible light irradiation as compared to their anatase counterparts. Keywords—Metal Loaded Nanoparticles, Dye Degradation, Photo-degradation, Photo-oxidation