Use of amorphous TiO₂ deposited on cotton by sol-gel process for de-colorization of direct dye solutions in presence of UV radiation

Abstract

In this investigation, decolorization of a direct dye solution catalysed by TiO₂ coated on a cotton fabric by sol- gel route in presence of UV radiation has been studied. Effect of various process and material parameters like initial dye solution concentration, treatment time and temperature, stirring rate and construction of fabric on dye decolorization extent has been studied. It is observed that with a starting dye solution concentration of 0.1 g/L, almost 80% dye removal can be achieved. It is not possible to improve the decolorization extent beyond 80% by any combination of parameters. X-ray diffraction studies reveal that the form of TiO₂ deposited on cotton fabric is not crystalline but amorphous in nature. While the UV radiation intensity and the fabric construction influence the dye decolorization, the treatment temperature and stirring rate do not have much bearing on decolorizing efficiency.