Photocatalytic degradation of Azure and Sudan dyes using nano $TiO_2$

Aarthi, T and Narahari, Prashanthi and Madras, Giridhar (2007) Photocatalytic degradation of Azure and Sudan dyes using nano $TiO_2$. In: Journal of Hazardous Materials, 149 (3). pp. 725-734.

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Abstract

The present study investigates the dependence of photocatalytic rate on molecular structure of the substrate that is degraded. The photocatalytic degradation of Azure (A and B) and Sudan (III and IV) dyes, having similar structure, but different functional groups, were investigated with two catalysts. The photocatalytic activity of solution combustion synthesized $TiO_2$ $(CS TiO_2)$ was compared with that of Degussa P-25 for degrading these dyes. The effect of solvents and mixed-solvent system on photodegradation of Sudan III was investigated. The photodegradation rate was found to be higher in solvents with higher polarity. The effect of $pH$ and the presence of metal ions in the form of chloride and nitrate salt, on degradation rate of Azure A was also investigated. The metal ions significantly reduced the photocatalysis rates. A detailed Langmuir–Hinshelwood kinetic model has been developed to explain the effect of metal ions on degradation rate of the substrate. This model elucidates the contribution of holes and electrons towards degradation of the dye.

Item Type:	Journal Article
Publication:	Journal of Hazardous Materials
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	Photocatalysis;Azure;Sudan;TiO2;Dye degradation;Combustion synthesis.
Department/Centre:	Division of Mechanical Sciences > Chemical Engineering
Date Deposited:	04 Jun 2008
Last Modified:	22 Feb 2012 06:19
URI:	http://eprints.iisc.ac.in/id/eprint/14163

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