In this research, we have designed a microwave-assisted procedure for processing of ZnO nanoparticles (ZnO NPs) modified by Montmorillonite K10 (MK10) nanosheets in a one-pot strategy using Carrisa edulis fruit extract as the capping agent. The sample was characterized with X-ray diffraction, infrared, ultraviolet–visible spectroscopy, transmission electron microscopy, X-ray diffraction, atomic force microscopy, zeta potential and photoluminescence. We observed that the ZnO/MK10 nanocomposite exhibited superior photocatalytic ability toward methylene dye (MB) degradation. ZnO/MK10 nanocomposite shows excellent sonophotocatalytic effect, which is three times higher than that of MB photocatalytic effect. This nanocomposite has been further active in trapping species, potential mechanism for sonophotocatalytic degradation, excellent recyclability and stability.