engleski

PROPERTIES OF ZnO PARTICLES PRECIPITATED BY RAPID HYDROLYSIS OF ZINC ACETYLACETONATE

The precipitation chemistry of zinc oxide (ZnO) has been extensively investigated, primarily because ZnO has found important applications, both in the traditional Technologies such as paints, catalysts, rubbers, cosmetics, and in advanced Technologies as sensors, photodetectors, LEDs and transistors. The nano/microstructure of ZnO in the form of powders or films is an important property of specific applications of this material. ZnO can be synthesized to possess various nano/microstructures and other properties by varying the chemistry and physical parameters in a corresponding synthesis. In the present work we have investigated the influence of experimental conditions on the nano/microstructure and optical properties of ZnO particles produced by rapid hydrolysis of zinc acetylacetonate at 160^(o)C. The samples were characterized with XRD, FE scanning electron microscopy, FT-IR, UV/Vis/NIR and photoluminiscence (PL)spectroscopies. XRD patterns of all samples were assigned to the hexagonal ZnO phase (wurtzite-type), as well as the corresponding FT-IR spectra. FE-SEM inspection showed high depen-dence of ZnO microstructure on the chemical composition of the reaction mixture and time of ageing during the rapid hydrolysis of zinc acetylacetonate. Microstructural differences were noticed between C2H5OH/H2O and H2O media, as well as under the influence of NH4OH adding. Aggregation of ZnO nanoparticles into much bigger ZnO particles (micron size) and issolution/recrystallization are found to be also important factors in the formation of different ZnO nano/microstructures. The band gap values for prepared ZnO samples were calculated on the basis of UV/Vis spectra recorded. PL spectra were recorded for ZnO samples in powder form and their suspensions in pure ethanol. A differences noticed will be discussed.

ZnO; Rapis hydrolysis; Nano/microstructure; Optical properties

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