Photocatalytic behaviour of sulphated TiO2 for phenol degradation

Photocatalytic oxidation of phenol was performed over sulphated TiO2 prepared by a sol–gel method. Comparison with non-sulphated TiO2 and sulphated Degussa was also made. Wide structural and surface characterisation of catalysts was carried out in order to establish a correlation between the effect of sulphation process on the TiO2 photocatalytic properties. Sulphation process clearly stabilizes TiO2 catalyst phase against sintering, maintaining anatase phase and relatively high surface area values with respect non-sulphated TiO2. In spite of sulphate loading should be higher at low temperatures, better conversion values for phenol oxidation has been obtained for samples calcined at 700 °C. For this calcination temperature, the optimisation of structural and surface area values lead to better photocatalytic performance in spite of sulphate presence and therefore acidic properties of samples should be dismissed. Sulphated TiO2 samples prepared by sol–gel presented higher photocatalytic conversions for temperatures higher than 600 °C.