Photocatalytic Activity of Toluene under UV-LED Light with TiO₂Thin Films

Abstract

Titanium dioxide (TiO 2) and ferric-doped TiO 2 (Fe-TiO 2) thin films were synthesized on the surface of 304 stainless steel sheets using a simplified sol-gel preparation method. The Fe-TiO 2 thin films were prepared with weight-to-volume ratios of Fe 3+ /TiO 2 of 0.3%, 0.5%, and 0.7%, respectively. The crystalline phase structures of the prepared TiO 2 and Fe-TiO 2 thin films were entirely anatase. The measured optical band gaps of the TiO 2 , 0.3% Fe-TiO 2 , 0.5% Fe-TiO 2 , and 0.7% Fe-TiO 2 thin 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 −1 mW −1 , for TiO 2 , 0.3% Fe-TiO 2 , 0.5% Fe-TiO 2 , and 0.7% Fe-TiO 2 , respectively. An increase in Fe 3+ 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.

Monitoring of TiO2-catalytic UV-LED photo-oxidation of cyanide contained in mine wastewater and leachate

“…There have been a lot of works on the photo-catalytic oxidation using UV-LED and TiO 2 (Chen et al, 2005;Vilhunen et al, 2010;Natarajan et al, 2011;Rojviroon et al, 2012;Wang et al, 2012;Jo and Tayade, 2014;Rasoulifard et al, 2014;Umar et al, 2015), but all of them dealt with photo-catalytic degradation of organic compounds. A few researches focused on the photo-oxidation of inorganic contaminants rather than organic compounds, especially on cyanide (Frank and Bard, 1977;Augugliaro et al, 1997Augugliaro et al, , 1999Ibrahim et al, 2003;Dabrowski et al, 2005;Marugán et al, 2009;Karunakaran et al, 2011;Ozcan et al, 2012;Bagabas et al, 2013).…”

Treatment of crystallized-fruit wastewater by UV-A LED photo-Fenton and coagulation–flocculation

“…Semiconductor LEDs technology are a directional light source with maximum intensity at an angle almost perpendicular to the surface emission. Although at a relatively high cost, LEDs lamps have several advantages when compared to traditional UV lamps e they do not over heat and have a longer lifetime, lower energy consumption and higher efficiency (Rojviroon et al, 2012;Natarajan et al, 2011).…”

New Generation Energy-Efficient Light Source for Photocatalysis: LEDs for Environmental Applications

“…Due to the advantage of LEDs over traditional ultraviolet light sources, LEDs have recently been employed for the removal of gases from air. It has been reported that various organic air pollutants, such as formaldehyde, glucose, isopropyl methyl phosphonofluride, dimethyl sulfide, 2-propanol, aceton vapors, tolune, and trichloroethylene, were degraded using different LEDs. ,− …”