NOBLE METAL IMPREGNATED TITANIA PHOTOCATALYST FOR THE
DEGRADATION OF TEXTILE DYES
Dr.R.Vaithiyanathan
Associate Professor, Department of Chemistry
Jerusalem College of Engineering,Velachery Main Road,
Narayanapuram, Pallikkaranai, Chennai-600 100, Tamilnadu, India
Contact No: 09444070610
Email id: sirkazhi74@gmail.com
ABSTRACT
Photocatalytic decolourisation of four different commertial textile azo dyes was studied
under UV irradiation (365 nm) using titania catalysts, synthesized via sol gel method. In order to
improve the photocatalytic activity of bare TiO2, silver metal impregnated titania catalysts
containing varying amount of silver metal from 0.5-2.0% were synthesized and their
photocatalytic activities towards the decolourization of selected dyes…show more content… This increase in the activity of silver doped titania catalyst may be due to
its lower band gap values and the effective separation of electron-hole recombination by silver
metal. However impregnation of silver beyond 1% reduced the photocatalytic activity of TiO2.
At higher concentration, the silver particle covers the active sites of titania which prevents light
absorption as well as the absorption of organic substrate from contacting the titania surface
thereby reducing the efficiency of TiO2 photocatalyst.
The results showed that titania containing 1% silver exhibited high photocatalytic activity
due to the following reasons; (i) its lower band gap value (3.07 eV) causes effective light
absorption and (ii) separation of electron-hole pair recombination by silver metal.
CONCLUSION
? TiO2 and silver (0.5-2 %) modified titania catalysts were synthesized via sol gel method.
? Silver impregnation decreased the band gap value of titania. Therefore all the silver impregnated titania catalysts showed higher photocatalytic activity