A Brief Note on the Temperature-Dependent Photocatalytic Degradation of Congo Red Using Zinc Oxide

Jacob White^1, and Whitney Smith¹

¹Chemistry Department, University of Rio Grande, Rio Grande, USA

Cite this paper:
Jacob White and Whitney Smith. A Brief Note on the Temperature-Dependent Photocatalytic Degradation of Congo Red Using Zinc Oxide. American Journal of Water Resources. 2013; 1(4):66-69. doi: 10.12691/ajwr-1-4-2

Abstract

Congo red, a conjugated diazo dye which is a derivative of benzidine and napthionic acid, has experienced commercial success because of its ability to dye cotton easily. The unregulated disposal of textile dyes, such as Congo red, has created a challenge for environmental chemists to determine effective, inexpensive treatment processes for remediating contaminated water. Studies involving semiconductors such as titanium dioxide (TiO₂) and zinc oxide (ZnO) have investigated their affects on wastewaters after being irradiated. However, few reports have described the influence temperature has on such systems. The objective of this study was to briefly characterize, via UV-Visible spectroscopic techniques, the temperature-dependency of the photocatalytic degradation of Congo red using zinc oxide and an inexpensive radiation source. The results indicate that the rate of degradation is catalytically dependent, photo-induced, and potentially temperature dependent with the greatest rate of degradation observed in trials conducted at low (~5°C) temperature. The results may also suggest the prevalence of aggregate dye formation at elevated (~40°C) temperature, although photocatalytic degradation is likely to occur concurrently.

Keywords:
Congo red textile dye water remediation water treatment photocatalysis

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References:

[1]	Wang, C. Wang, X., Xu, B. Enhanced Photocatalytic Performance of Nanosized Coupled ZnO/SnO2 Photocatalysts for Methyl Orange Degradation. Journal of Photochemistry and Photobiology. [Online] 2004, Volume 168, Issue 1-2, p47-52.
[2]	Akyol, A. Bayramoglu, M. The Degradation of an Azo Dye in a Batch Slurry Photocatalytic Reactor. Chemical Engineering and Processing. [Online] 2008, Volume 47, Issue 12, p2150-2156.
[3]	Movahedi, M., Mahjoub, A.R., Janitabar-Darzi, S. Photodegradation of Congo red in Aqueous Solution on ZnO as an Alternative Catalyst to TiO2. Journal of the Iranian Chemical Society. [Online] 2009, Volume 6, Issue 3, p570-577.
[4]	Ollis, D. Photocatalytic Purification and Remediation of Contaminated Air and Water. Comptes Rendus de lAcademie des Sciences Series IIC Chemistry. [Online] 2000, Volume 3, Issue 6, p405-411.
[5]	Chakrabarti, S., Dutta, B. Photocatalytic Degradation of Model Textile Dyes in Wastewater Using ZnO as Semiconductor Catalyst. Journal of Hazardous Materials. [Online] 2004, Volume 112, Issue 3, p269-278.
[6]	Valenzuela, M.A., Bosch, P., Jimenez-Becerril, J., Quiroz, O., Paez, A.I. Preparation, Characterization and Photocatalytic Acitivity of ZnO, Fe2O3 and ZnFe2O4. Journal of Photochemistry and Photobiology. [Online] 2002, Volume 148, Issue 1-3, p177.
[7]	Ma, H., Wang, M., Yang, R., Wang, W., Zhao, J. Shen, Z., Yao, S. Radiation Degradation of Congo Red in Aqueous Solution. Chemosphere. 2007, Volume 68, p1098-1104.
[8]	Wojnarovits, L., Palfi, T., Takacs, E., Emmi, S.S., Reactivity Differences of Hydroxyl Radicals and Hydrated Electrons in Destructing Azo Dyes. Radiat. Phys. Chem. 2005, Volume 74, 239-246.
[9]	Bumpus, J.A. Remediation of Water Contaminated with an Azo Dye: An Undergraduate Laboratory Experiment. Journal of Chemical Education. [Online] 1999, Volume 76, Issue 12, p1680.
[10]	Wahi, R.K., Yu, W.W., Liu, Y., Mejia, M.L., Falkner, J.C., Nolte, W., Colvin, V.L. Photodegradation of Congo Red Catalyzed by Nanosized TiO2. Journal of Molecular Catalysis A: Chemical. 2005, Volume 242, p48-56.
[11]	Habibi, M.H., Hassanzadeh, A., Zeini-Isfahani, A. Effect of Dye Aggregation and Azohydrazonetautomerism on the Photocatalytic Degradation of Solophenyl Red 3BL Azo Dye Using Aqueous TiO2 Suspension. Dyes and Pigments. 2006, Volume 69, p111-117.
[12]	Hihara, T., Okada, Y., Morita, Z. Photo-Oxidation and -Reduction of Vat Dyes on Water-Swollen Cellulose and Their Lightfastness on Dry Cellulose. Dyes and Pigments. 2002, Volume 53, p153-177.