Sol–gel synthesis of nanocrystalline TiO2 and the investigation of its photocatalytic activity for degradation of methyl orange

Abstract

This work presents the successful preparation of titanium dioxide (TiO2) by the sol-gel process in the presence of
polyethylene glycol with a molecular weight of 200 g/mol (PEG200) and crystallized after treatment with hot water at 90°C.
The photocatalytic decolorization of an azo dye model, methyl orange (MO) in aqueous medium was carried out in a
reactor with two UV lamps, using titanium dioxide containing PEG200 as catalyst. We investigated the effect of operating
conditions such as initial concentration of MO, the initial concentration of TiO2, the pH of the solution and the addition of
NaCl on the degradation of the dye. It was found that the kinetic of degradation of MO depends on the initial dye
concentration and initial concentration of TiO2. Moreover, the addition of NaCl did not favor the photodegradation of the
dye.