Journal article
(Original article)


The formation of CdS quantum dots and Au nanoparticles


Publication Details
Author(s): Schiener A, Schmidt E, Bergmann C, Seifert S, Zahn D, Krach A, Weihrich R, Magerl A
Publisher: Walter de Gruyter GmbH
Publication year: 2017
Volume: 232
Pages range: 39-46
ISSN: 2196-7105
Language: English

Abstract

We report on microsecond-resolved in-situ SAXS experiments of the early nucleation and growth behavior of both cadmium sulfide (CdS) quantum dots in aqueous solution including the temperature dependence and of gold (Au) nanoparticles. A novel free-jet setup was developped to access reaction times as early as 20 μs. As the signal in particular in the beginning of the reaction is weak the containment-free nature of this sample environment prooved crucial. The SAXS data reveal a two-step pathway with a surprising stability of a structurally relaxed cluster with a diameter of about 2 nm. While these develop rapidly by ionic assembly, a further slower growth is attributed to cluster attachment. WAXS diffraction confirms, that the particles at this early stage are not yet crystalline. This growth mode is confirmed for a temperature range from 25°C to 45°C. An energy barrier for the diffusion of primary clusters in water of 0.60 eV was experimentally observed in agreement with molecular simulations. To access reaction times beyond 100 ms, a stopped-drop setup -again contaiment- free is introduced. SAXS experiments on the growth of Au nanoparticles on an extended time scale provide a much slower growth with one population only. Further, the influence of ionizing X-ray radiation on the Au particle fromation and growth is discussed.



How to cite
APA: Schiener, A., Schmidt, E., Bergmann, C., Seifert, S., Zahn, D., Krach, A.,... Magerl, A. (2017). The formation of CdS quantum dots and Au nanoparticles. Zeitschrift fur Kristallographie - Crystalline Materials, 232, 39-46. https://dx.doi.org/10.1515/zkri-2016-1978

MLA: Schiener, Andreas, et al. "The formation of CdS quantum dots and Au nanoparticles." Zeitschrift fur Kristallographie - Crystalline Materials 232 (2017): 39-46.

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