Photocatalytic activity of toluene under UV-LED light with TiOthin films

Abstract

Titanium dioxide (TiO and ferric-doped TiO(Fe-TiO thin films were synthesized on the surface of 304 stainless steel sheets using a simplified sol-gel preparation method. The Fe-TiOthin films were prepared with weight-to-volume ratios of Fe3+/TiOof 0.3, 0.5, and 0.7, respectively. The crystalline phase structures of the prepared TiOand Fe-TiOthin films were entirely anatase. The measured optical band gaps of the TiO 0.3 Fe-TiO 0.5 Fe-TiO and 0.7 Fe-TiOthin films were 3.27, 3.28, 3.22, and 2.82 eV, respectively. The grain sizes and other physical properties of the prepared thin films were also reported. The kinetics of the photocatalytic processes under a UV-LED light source could be explained by the Langmuir-Hinshelwood kinetic model with the specific rates of 2.00×10-3, 4.00×10-3, 5.00×10-3, and 7.00×10-3 min-1mW-1, for TiO 0.3 Fe-TiO 0.5 Fe-TiO and 0.7 Fe-TiO respectively. An increase in Fe3+ dopant concentration could enhance the photocatalytic activity of toluene decomposition as a result of lower optical band gaps, smaller grain size, and higher surface area. © 2012 Thammasak Rojviroon et al.