Consequently, the reorganization and assembling of microsphere-like structures comprised of nanobats was further elucidated by ultrasonically breaking the microspheres that was shown in the previous Fig. 2(d). The formed nanobat-like structure was self-assembled in a circular fashion to build hollow microspheres. This happens because a few unbalanced charge centers were formed due to dissimilarities in the surface charges [40]. These centers attract the nanobats formed in the solution by rotating adjacent structure (e) to share identical orientation and by increasing reaction time (Figs. 2(d) and 7(f)), forming the sphere-like CuO microsphere assemblies.