Development of ZnO microstructures produced by rapid hydrolysis of zinc acetylacetonate

ZnO particles were produced combining the rapid hydrolysis of zinc acetylacetonate and autoclaving the precipitation systems at 220 °C. The possible influence of cetyltrimethylammonium bromide (CTAB) on the ZnO microstructure was also investigated. ZnO particles showed certain differences in their microstructure, although all of them were based on hexagonal symmetry (wurtzite-type crystal structure). The presence of hollow ZnO particles was also shown. All these particles showed their substructure, consisting of nanosize ZnO particles (crystallites) which built stable hexagons. The presence of lamellar substructure in the formation of hexagonal ZnO pyramids was also noticed. The corresponding mechanism included (a) rapid hydrolysis of zinc acetylacetonate yielding a ZnO phase, (b) formation of Zn(NH3)42+ complexes and partial dissolution of the ZnO phase, (c) decomposition of Zn(NH3)42+ complexes at autoclaving temperature, and (d) competitive reaction of Zn(OH)2 formation with transformation to ZnO.