World Applied Sciences Journal 3 (5): 738-741, 2008
ISSN 1818-4952
© IDOSI Publications, 2008
Corresponding Author: Hamid Reza Ebrahimi Afarani, Department of Chemistry, Faculty of Science, Islamic Azad University,
Majlessi Branch, Isfahan, Iran
738
Preparation of Metal Catalysts on Granule Glass for Degradation
of Textile Dyes as Environmental Contaminants
Hamid Reza Ebrahimi Afarani
Department of Chemistry, Science and Research, Campus, Islamic Azad University,Poonak, Tehran, Iran
Department of Chemistry, Faculty of Science, Islamic Azad University-Majlessi Branch, Isfahan, Iran
Abstract: Photocatalytic decolorization of azo-dyes in water has been examined in an external UV light
irradiation using nanostructured of binary zincite catalyst on granule glass as a semiconductor photocatalyst.
Nanostructure films of binary zincite have been prepared on granule glass by our technique. Their
photocatalytic performances were tested for degradation of Azo dyes in solution under UV irradiation. The
structure, surface and morphology properties of the nanostrucred zincite film on on granule glass have been
investigated by XRD, SEM techniques. The results showed that the binary zincite film coated on glass surface
have a very high photocatalytic performance under UV light.
Key words: Nano azo dye nanostructures sol-gel chemistry catalytic properties
INTRODUCTION photocatalysis has gained much attention in recent
Textile industries produce large volume of colored surfactants and certain dyes has been observed to be
dye effluents which are toxic and non-biodegradable. efficiently catalysed by irradiated semiconductors. In
These effluents cause a lot of damage to the environment. a waste treatment application it would be simpler if the
Various chemical and physical processes such as catalyst were immobilized, so the material would not have
precipitation, adsorption, air stripping, flocculation, to be separated from solution. Sol-gel chemistry has
reverse osmosis and ultrafiltration can be used for color recently evolved into a general and powerful approach for
removal from textile effluents. Water pollution is a major preparing inorganic materials. Thin films are one of the
concern in many countries. Several methods of water most important materials due to technological applications
purification have been practiced since many decades. [7]. These wide variety of applications are including
Semiconductor photocatalysis is a promising technique, photoluminescence and transparent semiconductor
for photodegradation of various hazardous chemicals [9], photocatalyst, piezoelectricity [10] gas sensors [11]
that are encountered in waste waters. The great UV light emitting devices [12, 13], varistors [14], Optical
significance of this technique is that, it can degrade devices [15]. Thin films have been prepared by various
(detoxify) various complex organic chemicals, which techniques, such as physical vapor deposition [16 ],
has not been addressed by several other methods of Chemical Vapor Deposition (CVD) [17] spray pyrolysis,
purification. The general classes of compounds that have sputtering [18, 19 ] Pulsed Laser Deposition (PLD) [20]
been degraded by semiconductor photocatalysis include: and sol-gel method [21-27]. One of the most important
alkanes, haloalkanes, aliphatic alcohols, carboxylic acids, advantages of sol-gel processing including, conventional
alkenes, aromatics, haloarornatics, polymers, surfactants, thin film deposition techniques, are the ease of chemical
herbicides, pesticides and dyes. Heterogeneous composition control, low temperature annealing and
photocatalytic oxidation (PCO) is a method to remove homogeneous of sol solution, these advantages make
low concentrations of organic contaminants [1-5]. The sol-gel processing a very attractive method especially
UV light excites electrons from the valence to conduction for preparation of thin films. Thin film photocatalysts
band of the semiconductor catalyst leaving holes behind. with their high photocatalytic ability, high stability,
The electrons-hole pairs can initiate redox reactions with convenient reuse, have received more and more attention.
surface species. The subject of semiconductor mediated However, there has been little success in finding thin film
years [6]. The degradation of toxic pollutants like phenols,