Comparative Study of the Adsorption of Thiols and Selenols on Au(111) and Au(100)

ARISNABARRETA, NICOLÁS; RUANO, GUSTAVO D.; LINGENFELDER, MAGALÍ; PATRITO, E. MARTÍN; COMETTO, FERNANDO P.

LANGMUIR

AMER CHEMICAL SOC

Lugar: Washington; Año: 2017

0743-7463

he effect of the Au crystalline plane on the adsorption of different thiols and selenols isstudied via reductive desorption (RD) and X-Ray Photoelectron Spectroscopy (XPS)measurements. SAMs using aliphatic (ATs) and aromatic thiols (ArTs) on both Au (111) and Au(100) were prepared. The electrochemical stability of these SAMs on both surfaces is evaluatedby comparing the position of the RD peaks. The longer the AT?s chain the more stable the SAMon Au (100) when compared to Au (111). By means of XPS measurements, we determine thatthe binding energy (BE) of the S 2p signal corresponding to the S atoms in the thiol/Au interface,commonly assigned at 162.0 eV, shifts 0.2 eV from Au (111) to Au (100) for SAMs preparedusing thiols with the C* (C atom bonded to S) in sp3 hybridization; such as ATs. However, whenthe thiol presents the C* with a sp2 hybridization, such as in the case of ArTs, the BE remains at162.0 eV regardless the surface plane. Selenol-based SAMs were characterized comparativ