In this paper, Zinc Oxide (ZnO) nanopowders are synthesized using acoustic cavitation by applying different temperature conditions. Synthesized nano-powders are characterized using X-ray diffraction, UV-visible spectroscopy, photoluminescence, scanning electron microscopy, energy dispersive spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. Synthesized ZnO nanoparticles are used as catalysts in the photo-degradation of Methylene Blue. The degradation time for Methylene Blue was found to be 45 minutes. Degradation efficiency by using ZnO nanoparticles is found to be greater than 98%. Furthermore, we have discussed the efficiency of dye degradation as well as the kinetic study of the photocatalytic process.