New aspects of the surface chemistry of sulfur on Au(111): Surface structures formed by gold-sulfur complexes

Abstract

Sulfur adsorption on gold surfaces has been extensively studied because of the key role of sulfur species in heterogeneous catalysis, and, more recently, due to the interest in the synthesis of anisotropic gold nanoparticles with potential applications in medicine that involves sulfide reduction. Here we report new surface structures for sulfur on Au(111) by combining in situ scanning tunneling microscopy in aqueous sodium sulfide solutions and density functional theory calculations. Our results show two related lattices, (3√3 × 3√3) R30°(θ = 0.22) and (√7 × √7) R19.1°(θ = 0.57), that involve AuS 3 complexes as building blocks. Gold-sulfur complexes are formed by the lifting of gold atoms from the substrate surface as revealed by density functional theory calculations. These species, intermediate between adsorbed S in the well-known (√3 × √3)-R30 ○ lattice and adsorbed polysulfides in organized rectangular structures, explain the surface coverage of gold vacancy islands, a fingerprint of S adsorption on Au(111).

Mechanism of MoS2 Growth on a Au(111) Surface: An Ab Initio Molecular Dynamics Study

“…This order is in line with the previous studies. , When the number of sulfur atoms exceeds one, they tend to occupy two fcc sites rather than forming a S 2 cluster. The widely accepted (√3 × √3)­R30° structure with a sulfur coverage of 0.33 is the most favorable configuration. , Our calculations also indicated a ground state curve characterized by (√3 × √3)­R30°. Thus, in the following studies, we considered only sulfur-passivated Au(111) with [(3√3 × 3√3)­R30°] periodicity.…”

“…The widely accepted (√3 × √3)R30°structure with a sulfur coverage of 0.33 is the most favorable configuration. 43,44 Our calculations also indicated a ground state curve characterized by (√3 × √3)R30°. Thus, in the following studies, we considered only sulfur-passivated Au(111) with [(3√3 × 3√3)R30°] periodicity.…”

Detection of PPB-Level H2S Concentrations in Exhaled Breath Using Au Nanosheet Sensors with Small Variability, High Selectivity, and Long-Term Stability

“…This adsorption structure is typical in S-adsorbed Au(111) systems. 71,72 In addition, we experimentally observed a {111} surface orientation of the Au nanosheet, as shown in Figure 2e and f. Thus, elucidating the PDOSs of the S atoms using this structure was reasonable. Figure 5c shows the calculated PDOSs of the S atoms.…”

“…We applied a ( ) R 30° Au(111) surface lattice with a surface S coverage θ S of 0.33; the S atoms were adsorbed at 3-fold fcc hollow sites, as shown in Figure b. This adsorption structure is typical in S-adsorbed Au(111) systems. , In addition, we experimentally observed a {111} surface orientation of the Au nanosheet, as shown in Figure e and f. Thus, elucidating the PDOSs of the S atoms using this structure was reasonable. Figure c shows the calculated PDOSs of the S atoms.…”

Determination of ascorbic acid at solid electrodes modified with L-cysteine

“…Scheme 1 shows that the L-cysteine is attached to the electrode surface via sulfur atoms. It is also known from the literature that the sulfur atom is very well attached to the voids on the gold surface [27]. Modification of the Au electrode by L-cysteine and the predicted binding pattern of ascorbic acid (AA) to the modified electrode surface are shown in Scheme 1.…”