Nucleation and Growth Kinetics of ZnO Nanoparticles Studied by in Situ Microfluidic SAXS/WAXS/UV-Vis Experiments
| Autor: | Stephan Förster, Maria Herbst, Eddie Hofmann |
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| Rok vydání: | 2019 |
| Předmět: |
In situ
Materials science Small-angle X-ray scattering Microfluidics Nucleation Nanoparticle Sequence (biology) 02 engineering and technology Surfaces and Interfaces 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences Ultraviolet visible spectroscopy Zno nanoparticles Chemical engineering Electrochemistry General Materials Science 0210 nano-technology Spectroscopy |
| Zdroj: | Langmuir : the ACS journal of surfaces and colloids. 35(36) |
| ISSN: | 1520-5827 |
| Popis: | The synthesis of ZnO nanoparticles proceeds through a complex sequence of precursor reactions, nucleation, and growth processes. For further advancement and control of nanoparticle synthesis, a detailed understanding of the mechanisms and kinetics is essential. With the recent advancement in X-ray scattering and spectroscopy methods, in situ experiments during nanoparticle synthesis can be performed, which provide important new insights into reaction and growth mechanisms. Here we use in situ small- and wide-angle X-ray scattering (SAXS, WAXS) coupled with UV-vis spectroscopy to investigate the nucleation and growth process of an oleate-based ZnO nanoparticle synthesis yielding narrowly disperse nanoparticles over the complete time scale from 30 s to 18 h. We find that the nucleation and early growth period during the first 1000 s can be quantitatively described by a classical homogeneous nucleation and growth mechanism. Furthermore, we identified a second growth phase where nanoparticle crystallization occurs, as indicated by the appearance of higher-order Bragg peaks and a pronounced shift of the absorption edge in the UV-vis spectra. The results are in very good agreement with recent studies on the use of the ZnO alkali hydroxide hydrolysis route. Thus, a very good understanding of the nucleation and growth mechanisms and kinetics of the most important ZnO synthesis routes has been established. |
| Databáze: | OpenAIRE |
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