6533b7d9fe1ef96bd126cefa

RESEARCH PRODUCT

Thiolate Adsorption on Au(hkl) and Equilibrium Shape of Large Thiolate-covered Gold Nanoparticles

Karoliina HonkalaGeorgios D. BarmparisIoannis N. Remediakis

subject

ChemistrytiheysfunktionaaliteoriaGeneral Physics and AstronomyNanoparticleDissociation (chemistry)kultaBond lengthCrystallographyMolecular geometryAdsorptionChemisorptionDensity functional theoryGoldPhysical and Theoretical ChemistryWulff constructionta116density functional theory

description

The adsorption of thiolates on Au surfaces employing density-functional-theory calculations has been studied. The dissociative chemisorption of dimethyl disulfide (CH3S−SCH3) on 14 different Au(hkl) is used as a model system. We discuss trends on adsorption energies, bond lengths, and bond angles as the surface structure changes, considering every possible Au(hkl) with h, k, l ≤ 3 plus the kinked Au(421). Methanethiolate (CH3S-) prefers adsorption on bridge sites on all surfaces considered; hollow and on top sites are highly unfavourable. The interface tensions for Au(hkl)-thiolate interfaces is determined at low coverage. Using the interface tensions in a Wulff construction method, we construct atomistic models for the equilibrium shape of large thiolate-covered gold nanoparticles. Gold atoms in a nanoparticle change their equilibrium positions upon adsorption of thiolates towards shapes of higher sphericity and higher concentration of step-edge atoms. peerReviewed

yearjournalcountryeditionlanguage
2013-01-01
http://urn.fi/URN:NBN:fi:jyu-201602031428