Time dependant UV–vis absorption spectra of (a) sonocatalytic, (b) photocatalytic, and (c) sonophotocatalytic degradation of crystal violet using MgTi2O5 nanoparticles. (d) Adsorption/degradation profile, (e) degradation curves, and (f) corresponding kinetic plots of crystal violet solution. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)