Abstract
Energetics, electronic structure, charging, and capacitive properties of bare and thiol-passivated gold nanocrystals were investigated via density-functional calculations. In the energy-optimized passivated nanocrystal, comprised of a truncated-octahedral face-centered-cubic core coated by a monolayer of 24 methylthiol molecules, we find interfacial charge transfer of about from the outermost gold atoms to the sulfur atoms. The estimated effective capacitance is 0.084 aF, correlating well with recent electrochemical measurements. Charging takes place within the molecular layer. Molecular adsorption of dimethyl-disulfide is found to be energetically unfavorable for a gold cluster of this size.
- Received 15 December 1998
DOI:https://doi.org/10.1103/PhysRevLett.82.3264
©1999 American Physical Society