Please use this identifier to cite or link to this item:
|Title: ||Photocatalytic destruction of gaseous toluene by porphyrin-sensitized TiO2 thin films|
|Authors: ||Pin-Chuan Yao|
|Keywords: ||Indoor air|
|Issue Date: ||2019-01-07T01:10:54Z
|Publisher: ||Journal of the Taiwan Institute of Chemical Engineers|
|Abstract: ||Abstract: Photocatalytic removal of indoor level of toluene in the gas phase was performed in a tubular reactor by TiO2-based photocatalysts under illumination of UV and visible light, respectively. Two types of TiO2 suspensions were employed in the whole experiments: one prepared by a sol–gel route (designated as SG-TiO2) and the other by applying a commercial Degussa P25 TiO2 (designated as P25-TiO2). All photocatalysts were dip coated on the inner surface of a Pyrex glass tube and followed by a post-annealing process. For visible-type photocatalysts, the above TiO2 films were sensitized by tetrakis (4-carboxyphenyl) porphyrin (TCPP) and designated as TCPP/SG-TiO2 and TCPP/P25-TiO2, respectively.
The photocatalytic destruction of gaseous toluene by the four catalysts was evaluated. For the UV-type photocatalysts, toluene was decomposed significantly by both types of TiO2 films at lower toluene concentrations, [T]o. However, the overall removal efficiency (RE) was decreased dramatically as the initial concentration of was elevated to 6.5 ppm for P25-TiO2 and 4.0 ppm for P25-TiO2, respectively. A plot of toluene elimination capacity (EC) versus toluene loading rate indicated that the limiting EC for the SG-TiO2 and P25-TiO2 was 4.9 and 2.7 mg/h/m2, respectively. In contrast, either type of dye-sensitized TiO2 photocatalysts evaluated under illumination of visible light showed relatively low toluene RE as compared to the UV-type photocatalysts under identical conditions. After pre-soaking in HCl solution, the activity of the acid-pretreated TCPP/P25-TiO2 [designated as TCPP/P25-TiO2 (ACT)] was improved considerably under the identical conditions.
The kinetics of photocatalytic decomposition of gaseous toluene in our study generally would follow the Langumuir–Hinshelwood (L–H) model. The rate constant k, as fitted by L–H model, for the SG-TiO2-based catalysts is larger than that of P25-TiO2-based catalysts while the absorption constant K, on the contrary, follows the different trend. The higher activity of SG-TiO2 could be attributed to the smaller grain size (4.6–8.1 nm) of anatase crystals as evaluated in XRD diffraction pattern.
|Relation: ||42(3) pp.470-479|
|Appears in Collections:||[應用地球科學研究所] 期刊論文|
Files in This Item:
All items in NTOUR are protected by copyright, with all rights reserved.