The formation of CdS quantum dots and Au nanoparticles

Journal article
(Original article)

Publication Details

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


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.

FAU Authors / FAU Editors

Bergmann, Christoph
Lehrstuhl für Kristallographie und Strukturphysik
Magerl, Andreas Prof. Dr.
Lehrstuhl für Kristallographie und Strukturphysik
Schiener, Andreas
Lehrstuhl für Kristallographie und Strukturphysik
Zahn, Dirk Prof. Dr.
Professur für Theoretische Chemie

Additional Organisation
Graduiertenkolleg 1896/2 In situ Mikroskopie mit Elektronen, Röntgenstrahlen und Rastersonden
Exzellenz-Cluster Engineering of Advanced Materials
Interdisziplinäres Zentrum, Center for Nanoanalysis and Electron Microscopy (CENEM)

External institutions
Argonne National Laboratory
Universität Regensburg

How to cite

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.

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


Last updated on 2019-03-06 at 16:23