Congo Red Photocatalytic Decolourization using Modified Titanium

Authors: A. López–Vásquez, D. Santamaría, M. Tibatá, C. Gómez

Abstract:

A study concerning the photocatalytic decolourization of Congo red (CR) dye, over artificial UV irradiation is presented. Photocatalysts based on a commercial titanium dioxide (TiO2) modified with transition metals (Ni, Cu and Zn) were used. The dopage method used was wet impregnation. A TiO2 sample without salt was subjected to the same hydrothermal treatment to be used as reference. Congo red solutions to several pH conditions (natural and basic) were used to evaluate photocatalytic performance of each doped catalysts. Photodecolourization percentage was measured spectrofotrometically after 3 h of treatment to 499 nm as response variable. Kinetics investigations of photodegradation indicated that reactions obey to Langmuir-Hinshelwood model and pseudo–first order law. The rate constant studies of photocatalytic decolourization reactions for Zn–TiO2 and Cu–TiO2 photocatalysts indicated that in all cases the rate constant of the reaction was higher than that of TiO2 undoped. These results show that nature of the metal modifying the TiO2 influence on the efficiency of the photocatalyst evaluated in process. Ni does not present an additional effect compared with TiO2, while Zn enhances the photoactivity due to its electronic properties.

Keywords: Congo red, Dopage, Photodecolourization, Titanium dioxide.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1070383

References:

[1] M.H. Habibi, S. Tangestananejad, B. Yadollahi, "Photocatalytic mineralisation of mercaptans as environmental pollutants in aquatic system using TiO2 suspension", Appl. Catal. B: Environ. vol. 33, no.1, pp. 57-63, Sept. 2001.
[2] V. Mirkhani, S. Tangestaninejad, M. Moghadam, M.H. Habibi and A. Rostami-Vartooni, "Photocatalytic Degradation of Azo Dyes Catalyzed by Ag Doped TiO2 Photocatalyst", J. Iran. Chem. Soc., vol. 6, no. 3, pp. 578-587, Sept. 2009.
[3] Serpone, N., Pelizzetti, E. (Eds), Photocatalysis Fundaments and Application, 2nd ed., New York: Wiley-Interscience, 1989, p. 236.
[4] X.Z. Li, F.B. Li, "The enhancement of photodegradation efficiency using Pt-TiO2 catalyst", Chemosphere vol. 48, no. 10, pp. 1103-1111. Sept. 2002.
[5] A.V. Rupa, D. Manikandan, D. Divakar, T. Sivakumar, "Effect of deposition of Ag on TiO2 nanoparticles on the photodegradation of Reactive Yellow-17", J. Hazard. Mater. vol. 147, no. 3, pp. 906-913. Aug. 2007.
[6] N. Sobana, M. Muruganadham, M. Swaminathan, J. "Nano-Ag particles doped TiO2 for efficient photodegradation of Direct azo dyes", J. Mol. Catal. A: Chem. vol. 258, no. 2, pp. 124-132. Oct. 2006.
[7] K. Chiang, T.M. Lim, L. Tsen, C.C. Lee, "Photocatalytic degradation and mineralization of bisphenol A by TiO2 and platinized TiO2", Appl. Catal. A: Gen. vol. 26, no. 2, pp. 225-237. Apr. 2004.
[8] A. Scalafani, J. Herrmann, "Influence of metallic silver and of platinumsilver bimetallic deposits on the photocatalytic activity of titania (anatase and rutile) in organic and aqueous media", J. Photochem. Photobiol. A:Chem., vol.113, no. 2, pp. 181-188. Feb. 1998.
[9] X. Fu, LA. Clark, Q.Yang. M.A. Anderson "Enhanced Photocatalytic Performance of Titania-Based Binary Metal Oxides: TiO2/SiO2 and TiO2/ZrO2", Environ. Sci. Technol. vol. 30, no. 2, pp. 647-653. Jan. 1996.
[10] López-Vásquez A., Ortiz E., Arias F., Colina-Márquez J., Machuca F., "Photocatalytic decolorization of Methylene Blue with two photoreactors". J. Adv. Oxid. Tech., vol. 11, no. 1, pp. 33-48. 2008.
[11] H. Lachheb, E. Puzenat, A. Houas, M. Ksibi, E. Elaloui, C. Guillard, J. Herrmann, "Photocatalytic degradation of various types of dyes (Alizarin S, Crocein Orange G, Methyl Red, Congo Red, Methylene Blue) in water by UV-irradiated titania", Appl. Catal. B: Environ., vol. 39, no. 1, pp.75-90. Nov. 2002.
[12] M.H. Habibi, S. Tangestaninejad, M. Khaledisardashti, "Photodegradation Kinetics of o-Nitroaniline (ONA),m-Nitroaniline (MNA), p-Nitroaniline (PNA), p-Bromoaniline (PBrA) and o- Chloroaniline (OClA) in Aqueous Suspension of Zinc Oxide", Polish J. Chem., vol. 78, no. 6, pp. 851- 860. Jun. 2004.
[13] A. Fujishima, T.N. Rao, D.A. Tryk, "Titanium dioxide photocatalysis" J. Photochem. Photobiol. C: Photochem. Vol 1. No. 1, pp. 1-21. Jun. 2000.