Photocatalytic of TiO2-SiO2 Thin Films Co-Doped with Fe3+ and Thio-Urea in the Degradation of Formaldehyde by Indoor and Outdoor Visible Lights
Author(s)
Charuwan Kaewtip,
Kamolporn Accanit,
Nat-a-nong Chaowai,
Kanokpun Areerat,
Pasuree Reanjaruan,
Virote Boonumnauyvitaya*
ABSTRACT
In this work the photocatalytic activity of TiO2-SiO2 thin films co-doped with Fe3+ and thio-urea in the degradation of the gaseous formaldehyde was investigaged by indoor and outdoor visible lights. The films were synthesized by Peroxo Titanic Acid (PTA) method. The physicochemical properties of prepared samples were characterized using SEM and UV-vis absorption spectroscopy. It was found that the average film thickness of all coated samples was about 394 ± 5 nm. The band gap energy of un-doped and co-doped photocatalysts was 3.08 and 2.88 eV, respectively. The photocatalytic experimental results showed that the co-doped TiO2-SiO2 thin film yield higher photocatalytic efficiency. Under the outdoor light (sunlight in the shade condition) irradiation, with the initial concentrations of formaldehyde of 1000, 3000 and 5000 ppmV, the efficiencies of formaldehyde degradation were 94.7 %, 89.5% and 85.1 %, respectively. Under the indoor light (the fluorescent lamp) irradiation, with the same formaldehyde initial concentrations, the photocatalytic activities were 87.4%, 85.3% and 81.5%, respectively.
In this work the photocatalytic activity of TiO2-SiO2 thin films co-doped with Fe3+ and thio-urea in the degradation of the gaseous formaldehyde was investigaged by indoor and outdoor visible lights. The films were synthesized by Peroxo Titanic Acid (PTA) method. The physicochemical properties of prepared samples were characterized using SEM and UV-vis absorption spectroscopy. It was found that the average film thickness of all coated samples was about 394 ± 5 nm. The band gap energy of un-doped and co-doped photocatalysts was 3.08 and 2.88 eV, respectively. The photocatalytic experimental results showed that the co-doped TiO2-SiO2 thin film yield higher photocatalytic efficiency. Under the outdoor light (sunlight in the shade condition) irradiation, with the initial concentrations of formaldehyde of 1000, 3000 and 5000 ppmV, the efficiencies of formaldehyde degradation were 94.7 %, 89.5% and 85.1 %, respectively. Under the indoor light (the fluorescent lamp) irradiation, with the same formaldehyde initial concentrations, the photocatalytic activities were 87.4%, 85.3% and 81.5%, respectively.
Cite this paper
C. Kaewtip, K. Accanit, N. Chaowai, K. Areerat, P. Reanjaruan and V. Boonumnauyvitaya, "Photocatalytic of TiO2-SiO2 Thin Films Co-Doped with Fe3+ and Thio-Urea in the Degradation of Formaldehyde by Indoor and Outdoor Visible Lights," Advances in Materials Physics and Chemistry, Vol. 2 No. 4, 2012, pp. 40-44. doi: 10.4236/ampc.2012.24B012.
C. Kaewtip, K. Accanit, N. Chaowai, K. Areerat, P. Reanjaruan and V. Boonumnauyvitaya, "Photocatalytic of TiO2-SiO2 Thin Films Co-Doped with Fe3+ and Thio-Urea in the Degradation of Formaldehyde by Indoor and Outdoor Visible Lights," Advances in Materials Physics and Chemistry, Vol. 2 No. 4, 2012, pp. 40-44. doi: 10.4236/ampc.2012.24B012.
References
[1] S. Photong and V. Boonamnuayvitaya, "Preparation and characterization of amine-functionalized SiO2/TiO2 films for formaldehyde degradation," Appl. Surf. Sci., vol. 255, pp. 9311-9315, 2009. [2] A. Fujishima and X. Zhang, "Titanium dioxide photocatalysis: present situation and future approaches," C.R. Chim., vol. 9, pp. 750-760, 2006. [3] Y. Yu, J. Wang, and J.F. Parr, "Preparation and properties of TiO2/fumed silica composite photocatalytic materials," Procedia Engineering, vol. 27, pp. 448-456, 2012. [4] Y. Wu, J. Zhang, L. Xiao, and F. Chen, "Properties of carbon and iron modified TiO2 photocatalyst synthesized at low temperature and photodegradation of acid orange 7 under visible light," Appl. Surf. Sci., vol. 256, pp. 4260-4268, 2010. [5] X. Yang, "Photo-catalytic degradation of Rhodamine B on C-, S-, N-, and Fe-doped TiO2 under visible-light irradiation," Appl. Catal., B, vol. 91, pp. 657-662, 2009. [6] B. Ahmmad, Y. Kusumoto, and M.S. Islam, "One-step and large scale synthesis of non-metal doped TiO2 submicrospheres and their photocatalytic activity," Adv. Powder Technol., vol. 21, pp. 292-297, 2010. [7] B. Tryba, "Increase of the Photocatalytic Activity of TiO2 by Carbon and Iron Modifications," Int. J. Photoenergy, vol. 2008, pp. 2008. [8] W.-X. Liu, J. Ma, X.-G. Qu, and W.-B. Cao, "Hydrothermal synthesis of (Fe, N) co-doped TiO2; powders and their photocatalytic properties under visible light irradiation," Res. Chem. Intermed., vol. 35, pp. 321-328, 2009. [9] Z. Liu, Y. Wang, W. Chu, Z. Li, and C. Ge, "Characteristics of doped TiO2 photocatalysts for the degradation of methylene blue waste water under visible light," J. Alloys Compd., vol. 501, pp. 54-59, 2010. [10] T. Ohno, Z. Miyamoto, K. Nishijima, H. Kanemitsu, and F. Xueyuan, "Sensitization of photocatalytic activity of S- or N-doped TiO2 particles by adsorbing Fe3+ cations," Appl. Catal., A, vol. 302, pp. 62-68, 2006. [11] X. Sun, H. Liu, J. Dong, J. Wei, and Y. Zhang, "Preparation and Characterization of Ce/N-Codoped TiO2 Particles for Production of H2 by Photocatalytic Splitting Water Under Visible Light," Catal. Lett., vol. 135, pp. 219-225, 2010. [12] C. Kaewtip, P. Chadpunyanun, and V. Boonamnuayvitaya, "Effect of Co-Dopants in TiO2–SiO2 Thin films on the Formaldehyde Degradation," Water Air Soil Pollut., vol. 223, pp. 1455-1465, 2012. [13] L. Ge, M. Xu, and H. Fang, "Synthesis of titanium oxide layers on glass substrates with aqueous refluxed sols (RS) and photocatalytic activities," J. Mater. Sci., vol. 42, pp. 4926-4934, 2007. [14] M. Yao, J. Chen, C. Zhao, and Y. Chen, "Photocatalytic activities of Ion doped TiO2 thin films when prepared on different substrates," Thin Solid Films, vol. 517, pp. 5994-5999, 2009. [15] X. Cheng, X. Yu, and Z. Xing, "One-step synthesis of Fe-N-S-tri-doped TiO2 catalyst and its enhanced visible light photocatalytic activity," Mater. Res. Bull., vol. pp. in press. [16] Y. Cong, J. Zhang, F. Chen, M. Anpo, and D. He, "Preparation, Photocatalytic Activity, and Mechanism of Nano-TiO2 Co-Doped with Nitrogen and Iron (III)," J. Phys. Chem. C, vol. 111, pp. 10618-10623, 2007. [17] T. Oyama, "Solar photocatalysis, photodegradation of a commercial detergent in aqueous TiO2 dispersions under sunlight irradiation," Sol. Energy, in press.
[1] S. Photong and V. Boonamnuayvitaya, "Preparation and characterization of amine-functionalized SiO2/TiO2 films for formaldehyde degradation," Appl. Surf. Sci., vol. 255, pp. 9311-9315, 2009. [2] A. Fujishima and X. Zhang, "Titanium dioxide photocatalysis: present situation and future approaches," C.R. Chim., vol. 9, pp. 750-760, 2006. [3] Y. Yu, J. Wang, and J.F. Parr, "Preparation and properties of TiO2/fumed silica composite photocatalytic materials," Procedia Engineering, vol. 27, pp. 448-456, 2012. [4] Y. Wu, J. Zhang, L. Xiao, and F. Chen, "Properties of carbon and iron modified TiO2 photocatalyst synthesized at low temperature and photodegradation of acid orange 7 under visible light," Appl. Surf. Sci., vol. 256, pp. 4260-4268, 2010. [5] X. Yang, "Photo-catalytic degradation of Rhodamine B on C-, S-, N-, and Fe-doped TiO2 under visible-light irradiation," Appl. Catal., B, vol. 91, pp. 657-662, 2009. [6] B. Ahmmad, Y. Kusumoto, and M.S. Islam, "One-step and large scale synthesis of non-metal doped TiO2 submicrospheres and their photocatalytic activity," Adv. Powder Technol., vol. 21, pp. 292-297, 2010. [7] B. Tryba, "Increase of the Photocatalytic Activity of TiO2 by Carbon and Iron Modifications," Int. J. Photoenergy, vol. 2008, pp. 2008. [8] W.-X. Liu, J. Ma, X.-G. Qu, and W.-B. Cao, "Hydrothermal synthesis of (Fe, N) co-doped TiO2; powders and their photocatalytic properties under visible light irradiation," Res. Chem. Intermed., vol. 35, pp. 321-328, 2009. [9] Z. Liu, Y. Wang, W. Chu, Z. Li, and C. Ge, "Characteristics of doped TiO2 photocatalysts for the degradation of methylene blue waste water under visible light," J. Alloys Compd., vol. 501, pp. 54-59, 2010. [10] T. Ohno, Z. Miyamoto, K. Nishijima, H. Kanemitsu, and F. Xueyuan, "Sensitization of photocatalytic activity of S- or N-doped TiO2 particles by adsorbing Fe3+ cations," Appl. Catal., A, vol. 302, pp. 62-68, 2006. [11] X. Sun, H. Liu, J. Dong, J. Wei, and Y. Zhang, "Preparation and Characterization of Ce/N-Codoped TiO2 Particles for Production of H2 by Photocatalytic Splitting Water Under Visible Light," Catal. Lett., vol. 135, pp. 219-225, 2010. [12] C. Kaewtip, P. Chadpunyanun, and V. Boonamnuayvitaya, "Effect of Co-Dopants in TiO2–SiO2 Thin films on the Formaldehyde Degradation," Water Air Soil Pollut., vol. 223, pp. 1455-1465, 2012. [13] L. Ge, M. Xu, and H. Fang, "Synthesis of titanium oxide layers on glass substrates with aqueous refluxed sols (RS) and photocatalytic activities," J. Mater. Sci., vol. 42, pp. 4926-4934, 2007. [14] M. Yao, J. Chen, C. Zhao, and Y. Chen, "Photocatalytic activities of Ion doped TiO2 thin films when prepared on different substrates," Thin Solid Films, vol. 517, pp. 5994-5999, 2009. [15] X. Cheng, X. Yu, and Z. Xing, "One-step synthesis of Fe-N-S-tri-doped TiO2 catalyst and its enhanced visible light photocatalytic activity," Mater. Res. Bull., vol. pp. in press. [16] Y. Cong, J. Zhang, F. Chen, M. Anpo, and D. He, "Preparation, Photocatalytic Activity, and Mechanism of Nano-TiO2 Co-Doped with Nitrogen and Iron (III)," J. Phys. Chem. C, vol. 111, pp. 10618-10623, 2007. [17] T. Oyama, "Solar photocatalysis, photodegradation of a commercial detergent in aqueous TiO2 dispersions under sunlight irradiation," Sol. Energy, in press.