Thiol Adsorption on the Au(100)-hex and Au(100)-(1 × 1) Surfaces

GRUMELLI, DORIS ELDA; LUCILA CRISTINA; FLAVIA LOBO MAZA; PILAR CARRO; KLAUS KERN; JULIO FERRON

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Lugar: Washington; Año: 2015 p. 14248 - 14254

1932-7447

Alkanethiol adsorption on the Au(100) surfaces is studied by usingscanning tunneling microscopy, X-ray photoelectron spectroscopy, and electrochemicaltechniques. Adsorption of hexanethiol (HT) on the Au(100)-hex surfaceresults in the formation of elongated Au islands following the typical stripes of thereconstruction. Ordered molecular arrays forming hexagonally distorted squarepatterns cover the stripes with surface coverage ≈0.33. On the other hand, HTadsorption on the Au(100)-(1 × 1) surface shows the absence of the elongatedisland and the formation of square molecular patterns with a surface coverage ≈0.44.The core level shift of thiolates adsorbed on the Au(100)-(1 × 1) and Au(111) isonly 0.15 eV, suggesting that chemistry rather than surface sites determines thebinding energy of the S 2p core level. These results are also important to completeour knowledge of the chemistry and surface structure for small thiolated AuNPswhere the Au(100) together with the Au(111) are the dominant faces.