The formation of CdS quantum dots and Au nanoparticles

Beitrag in einer Fachzeitschrift
(Originalarbeit)


Details zur Publikation

Autor(en): Schiener A, Schmidt E, Bergmann C, Seifert S, Zahn D, Krach A, Weihrich R, Magerl A
Zeitschrift: Zeitschrift fur Kristallographie - Crystalline Materials
Verlag: Walter de Gruyter GmbH
Jahr der Veröffentlichung: 2017
Band: 232
Seitenbereich: 39-46
ISSN: 2196-7105
Sprache: Englisch


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.



FAU-Autoren / FAU-Herausgeber

Bergmann, Christoph
Lehrstuhl für Kristallographie und Strukturphysik
Magerl, Andreas Prof. Dr.
Lehrstuhl für Kristallographie und Strukturphysik
Schiener, Andreas
Lehrstuhl für Kristallographie und Strukturphysik


Zusätzliche Organisationseinheit(en)
Graduiertenkolleg 1896/2 In situ Mikroskopie mit Elektronen, Röntgenstrahlen und Rastersonden
Exzellenz-Cluster Engineering of Advanced Materials


Autor(en) der externen Einrichtung(en)
Argonne National Laboratory
Universität Regensburg


Zitierweisen

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.

BibTeX: 

Zuletzt aktualisiert 2018-10-11 um 13:53