Ultrasound-Assisted Solution Synthesis and Characterization of Sea Urchin-Like ZnO Hierarchical Microstructures
ZnO hierarchical microstructures with uniform sea urchin-like morphology have been successfully synthesized through a facile and reliable ultrasound irradiation route by using Zn(CH3COO)2•2H2O and KOH as raw materials. The ZnO sample is investigated with XRD, SEM, TEM and HRTEM. Results indicate that the as-prepared sea urchin-like ZnO microstructures are assembled by numerous needle-like nanocrystals with the size about 2µm in length and about 100nm in diameter. The preferred growth orientation of these ZnO nanoneedles are along  direction. A blue shift in UV-vis absorption spectrum of the as-prepared ZnO sample is observed.
Zhiming Shi, Junhui Dong and Wen Ma
Y. W. Li et al., "Ultrasound-Assisted Solution Synthesis and Characterization of Sea Urchin-Like ZnO Hierarchical Microstructures", Advanced Materials Research, Vols. 602-604, pp. 209-213, 2013