Selenium Adsorption on Au(111) and Ag(111) Surfaces: Adsorbed Selenium and Selenide Films

Abstract

Results of a high resolution photoemission and electrochemistry study of Se adsorption on Au(111) and Ag(111) surfaces performed by immersion of pristine samples into an aqeuous solution of Na 2 Se are presented. Cyclic voltammetry on Au shows formation of selenium adsorbed species and the structures observed in reductive desorption are related to the atomic and polymeric species observed in XPS. In the case of Au(111) XPS spectra in the Se(3d) region indeed show two main features attributed to Se chemisorbed atomically and polymeric Se 8 features. Smaller structures due to other types of Se conformations were also observed. The Au(4f) peak line shape does not show core level shifts indicative of Au selenide formation. In the case of silver, XPS spectra for the Ag(3d) show a broadening of the peak and a deconvolution into Ag B bulk like and Ag Se components shows that the Ag Se is located at a lower binding energy, an effect similar to oxidation and sulfidation of Ag. The Se(3d) XPS spectrum is found to be substantially different from the Au case and dominated by atomic type Se due to the selenide, though a smaller intensity Se structure at an energy similar to the Se 8 structure for Au is also observed. Changes in the valence band region related to Se adsorption are reported.

Spontaneously Deposited Rh on Au(111) Observed by AFM and XPS: Electrocatalysis of Hydrogen Evolution

“…Photoelectron line Au 4f 5/2 is fitted to two components: one at (88.07 eV) corresponding to the metallic state of bulk Au(111) although slightly shifted than previously reported in the literature for Au(111), 46 tured gold surface. 47 Relative intensity of surface, Is, to bulk, Ib, component of Au 4f 5/2 line is 0.24, while their separation is 1.27 eV. Phoptoelectron line Au 4f 7/2 is also fitted to two components: one at (84.4 eV), and the shoulder at 83.9 eV, corresponding to bulk Au(111) and to restuctured surface atoms, respectively, are also slightly shifted compared to literature data, 47 most likely due to the previous exposure of the electrode to the ambient conditions.…”

“…47 Relative intensity of surface, Is, to bulk, Ib, component of Au 4f 5/2 line is 0.24, while their separation is 1.27 eV. Phoptoelectron line Au 4f 7/2 is also fitted to two components: one at (84.4 eV), and the shoulder at 83.9 eV, corresponding to bulk Au(111) and to restuctured surface atoms, respectively, are also slightly shifted compared to literature data, 47 most likely due to the previous exposure of the electrode to the ambient conditions. 48 Is/Ib ratio is 0.23, and their separation is 0.5 eV, slightly higher than reported earlier, 47 most likely due to the higher roughness of the initial Au(111), prepared electrochemically.…”

Colloidal and Deposited Products of the Interaction of Tetrachloroauric Acid with Hydrogen Selenide and Hydrogen Sulfide in Aqueous Solutions

“…The assignment of the Au 4f components is not straightforward, particularly, since AuSe contains two sorts of Au atoms, the oxidation state of which is a matter of dispute [35][36][37][38][39][40][41][42][43][44][45]. The Au 4f 7/2 peaks at 84.0-84.4 eV reported for gold-gold selenide [39][40][41], gold-CdSe [44,45]), adlayers of Se or alkyl selenides at Au [45][46][47][48][49]59], etc., originate from Au 0 surfaces but not AuSe phases. In nanostructured AuSe with admixture of Au [42], the values of 83.7 eV and 84.9 eV have been found, along with Se 3d 5/2 line at 54.5 eV, and ascribed to Au 0 and Au + , respectively; nevertheless, the authors assert the mixed valence state of gold (Au + Au 3+ Se 2 ).…”

“…Particularly, Cueva et al [45] have concluded from X-ray photoelectron spectroscopy (XPS) analysis that the shells deposited on CdSe NPs are most probably composed of AuSe or AuSeCl, which are instable and transform into dot-shaped Au 0 particles under the electron beam in Transmission electron microscopy (TEM). Several studies on adsorption of selenium [46,47] and alkylselenides on gold and Au NPs [48,49] have revealed no AuSe phases and, for example, demonstrated that alkylselenides replace alkylsulfides due to favored Au-Se bonding.…”

Laser Ablation Synthesis of Gold Selenides by using a Mass Spectrometer as a Synthesizer: Laser Desorption Ionization Time‐of‐Flight Mass Spectrometry

“…Some other dimer,t rimer,a nd chain-like selenium structuresw ere also detected. [21,22] Selenium clusters generated through laser ablation (LA) of seleniumo rd etected in seleniumvapors have been reported. [23][24][25][26][27][28][29][30][31] The structure of selenium clusters has been extensively studied.…”