Lifetime and Regeneration Studies of Various Supported TiO2Photocatalysts for the Degradation of Phenol under UV-C Light in a Batch Reactor

Combined photolysis and predominantly photocatalytic degradation of phenol under UV-C light (λ = 254 nm) with the maximum intensity of 5400 μW/cm2 was carried out in a batch reactor. The TiO2 photocatalysts were supported on glass beads, silica gel, and quartz sand using a sol−gel method. The supported TiO2 catalysts were characterized by XRD, SEM, and EDX analyses. Factors affecting the photocatalytic degradation of phenol such as pH, oxygen supply rate, initial phenol concentration, and H2O2 concentration were investigated. TiO2 supported on quartz sand gave the highest efficiency with 90% degradation of 50 mg/L phenol solution in 6 h, followed by TiO2 supported on silica gel and glass beads with 86% and 74%, respectively. The higher photoactivity of supported TiO2 on quartz sand was ascribed to the high crystallinity and high quantity of Ti, and the absence of ions which could inhibit the crystallization on the catalyst surface. The supported TiO2 was found to be stable for repeated use. The results su...