TiO2 nanofibre assisted photocatalytic degradation of Reactive Blue 19 dye from aqueous solution

Abstract

The photocatalytic degradation of Reactive Blue 19 (RB19) dye has been studied using TiO₂ nanofibre as the photocatalyst in aqueous solution under UV irradiation. Titanium dioxide nanofibre was prepared using a templating method with tetraisopropylorthotitanate as a precursor. The experiments were carried out in the presence of the TiO₂ nanofibre, and the effects of pH and electron acceptors on the degradation process were investigated. In order to observe the quality of the aqueous solution, chemical oxygen demand (COD) measurements were also carried out before and after the treatments. The photocatalytic decomposition of RB19 was most efficient in acidic solution. With the addition of hydrogen peroxide and potassium persulphate, as electron acceptors, into illuminated TiO₂ nanofibre suspensions, a synergistic effect was observed leading to an enhancement of the decolorization. From experimental results, under the condition of 1 g TiO₂ nanofibre L⁻¹, pH 3, and UVC light irradiation, decolorization would be complete in two hours. A significant decrease in the COD values was observed, which clearly indicates that the photocatalytic method offers good potential for the removal of RB19 from aqueous solution. The kinetic of photocatalytic removal of RB19 followed the Langmuir–Hinshelwood model. These results suggest that TiO₂ nanofibres with UV photocatalysis can be envisaged as a method for the treatment of coloured wastewaters, in particular in textile industries.