Sonocatalytic degradation of organic dyes and influence of Al₂O₃, Y₂O₃ and Fe₂O₃ on catalytic activity of TiO₂ under ultrasonic irradiation

In order to improve the sonocatalytic activity of TiO₂, Al₂O₃/TiO₂, Y₂O₃/TiO₂ and Fe₂O₃/TiO₂ composites were prepared using mechanical mixing, liquid boiling, ultrasonic dispersion and heat-treated methods. And then, a series of degradation experiments were carried out under ultrasonic irradiation. Also, the influences of heat-treated temperature and heat-treated time on the sonocatalytic activity of Al₂O₃/TiO₂, Y₂O₃/TiO₂ and Fe₂O₃/TiO₂, and ultrasonic irradiation time and solution acidity on the sonocatalytic degradation of Acid red B were investigated by UV-vis spectra. It was found that the degradation ratio showed significant increase in the order TiO₂ < Fe₂O₃/TiO₂ < Y₂O₃/TiO₂ < Al₂O₃/TiO₂. And the corresponding percentage degradations are about 37, 45, 52 and 81%, respectively. In addition, for exploring the universality, the degradation of other several organic dyes was also reviewed under the same conditions. Because of good degradation efficiency, this method may be an advisable choice for the treatment of non- or low-transparent wastewaters in the future.