Effect of ultrasonic frequency on the structure and sonophotocatalytic property of CdS/TiO2 nanocomposite

Visible-light-induced nano CdS/TiO2 sonophotocatalysts with different morphologies and particle sizes were prepared under multi-bubble sonoluminescence condition with different ultrasonic frequencies. The characterization and property studies were performed by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, UV–vis diffuse reflectance spectroscopy and surface area measurement, etc. In addition, we discussed the mechanical effects of shockwave formed from ultrasound-induced cavitation and investigated the degradation of methyl orange under simultaneous sonolysis and photocatalysis, i.e. sonophotocatalysis, in the presence of the CdS/TiO2 nanoparticles. The results suggest that the compactness, crystallinity and grain size of CdS/TiO2 nanocomposites produced are governed by the applied frequency, which in turn influence the sonophotocatalytic activity.