Photocatalytic degradation of volatile organics on TiO 2 embedded glass spherules

Abstract

This work investigates the feasibility of applying photocatalytic technology for removal of volatile organic compounds (VOCs) over TiO 2. A photocatalytic packed bed reactor (PPBR) was employed to determine the oxidation rates of VOCs (bezene, toluene, o-, m-, p- xylenes). TiO 2 Degussa P25 was used to prepare a nanocrystalline titania paste, where glass spherules were embedded. The photocatalyst was extensively characterized by means of spectroscopy (Raman, XRD) and microscopy (SEM, AFM). Experiments were conducted under ‘real world setting’ condition of temperature (25 °C ±2) and humidity (60%) while the irradiation was provided by 15 W near UV lamps. The dependence of the reaction rate on light intensity as well as the deactivation of the catalyst were determined. The results indicate that the rate of the photo-oxidation process increased while increasing the intensity of UV irradiation. Using two (2) UV-A lamps, the destruction rate of benzene and toluene was 0.0429 and 0.1960 μg m −2 h −1 respectively, while with four (4) UV-A lamps values of 0.6775 and 1.5301 μg m −2 h −1 correspondingly were obtained. The stabilized photocatalysts present remarkable stability (no deactivation and excellent repeatability). Reproducibility tests proved that the photocatalytic activity of the photocatalyst remains intact even after thirty consecutive experiments of new added VOCs quantities.