Formation Mechanisms of ZnO Spherulites and Derivatives
Formation Mechanisms of ZnO Spherulites and Derivatives
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DOI：
10.1021/acs.cgd.8b01332
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发表时间：
2019-01-01
影响因子：
3.8
通讯作者：
Zhou, Wuzong
中科院分区：
文献类型：
--
作者：
Connolly, Bethany M.;Greer, Heather F.;Zhou, Wuzong
ZnO microparticles have been solvothermally synthesized from zinc acetate and formic acid. The resulting microspherulites consist of radially arranged nanorods which undergo a range of recrystallization pathways to produce particles with different terminal morphologies. Crystallization on the particle surface results in hexagonal microdisc decorated hierarchical micro spheres. These particles expose only the (0001) crystallographic plane of ZnO and further develop into a sea-urchin-like morphology, when the microdiscs grow up along the [0001] direction into hexagonal microrods. Alternatively, crystallization of the particle core into a ZnO plate facilitates asymmetric assembly of nanocrystallites, forming a hexagonal cone on one side of the plate. The particle has a mushroom-like terminal morphology. When simultaneous surface and core recrystallization takes place, wood gyro-shaped particles are observed, in which all the surface discs face a single direction. The microstructures of the particles were investigated using XRD, electron microscopy, and surface coloring with adsorbed charged dyes. Structural studies of the early growth stages and subsequent morphology evolution support a dipole field driven formation mechanism. This work offers an improved understanding of the formation of other spherulites, in particular, naturally occurring mineral calcium carbonate spherulites.
