Stuttgart 2012 – scientific programme
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MO: Fachverband Molekülphysik
MO 3: Quantum Chemistry
MO 3.7: Talk
Monday, March 12, 2012, 15:45–16:00, V38.02
DFT Study of Charged Gold Clusters in Different Environments — •Alexander Held and Michael Walter — FMF Uni Freiburg, Germany
The charge dependent cluster capacitance C(z) of gold nanoparticles is investigated in different environments using density functional theory (DFT) calculations.
In the gas phase, C(z) is influenced primarily by electronic shell closing effects and the spatial extent of the excess charge. For gold nanoparticles prepared in a wet chemical process, the ligands may affect the cluster capacitance in different ways. Recent experimental results show evidence for quantized charging effects of quasi-unprotected gold nanoparticles in the ionic liquid [C4mim][BF4] for the first time. A peak like shape of C(z) has been observed. This feature is reproduced by our DFT model calculations and is found to originate from a polarity inversion of the ionic liquid surrounding the nanoparticles [1].
Furthermore, the DFT results are interpreted with an electrostatic model. Within the parameters of this model, different shapes of C(z) occur, suggesting further experimental investigations and comparison to other theoretical approaches.
[1] S. F. L. Mertens, C. Vollmer, A. Held, M. H. Aguirre, M. Walter, C. Janiak and T. Wandlowski, Angew. Chem. Int. Ed. 2011, 41, 9735 – 9738