Discoloration and degradation of textile dye aqueous solutions with titanium oxide catalysts obtained by the sol–gel method

In this work, we report the preparation of TiO2 catalysts by the sol–gel method from two different alkoxide precursors: titanium (IV) tetrabutoxy and titanium (IV) isopropoxide, called TiO2-TBOTC and TiO2-IPOTC, respectively. The catalysts were used in the photocatalytic discoloration and degradation of textile dye C.I. reactive orange-122 aqueous solutions. TiO2-TBOTC discolored dye solutions 100% in 40 min with maximum TOC reduction of 65.8%, in contrast to TiO2-IPOTC, which required 20 min of reaction and yielded maximum TOC reduction of 27.7%. Photocatalyst TiO2-TBOTC is more efficient than TiO2-IPOTC.