Characterization of thiolate species formation on Cu(111) using soft x-ray photoelectron spectroscopy

Abstract

Soft x-ray photoelectron spectroscopy of the S 2p levels at relatively high spectral resolution has been used to characterize the interaction of methanethiol, , ethanethiol, and dimethyl disulphide, with a Cu(111) surface at temperatures from approximately 130 K to 500 K. The results are consistent with previous reports of the formation of a surface thiolate species at intermediate temperatures, but also provide clear evidence for two distinct surface intermediates in addition to the intact molecules and chemisorbed atomic sulphur reported previously for this surface. These two intermediates appear to be similar to the two thiolate species reported in studies on Ni(111). Prior structural studies of the surface at room temperature show the surface to be reconstructed, and the lower temperature species identified here is assigned to a thiolate species on an unreconstructed surface, reconstruction being hindered at low temperatures. Additional evidence is found for two different atomic sulphur states in a narrow temperature range.

Adsorption behavior of (CH3)2S on sputtered and annealed Rh(100) surface by AFM, XPS and NEXAFS

“…It is clear that an additional component is generated in proportion to increase of the temperature, which takes the position of the binding energy between atomic S and DMS. This middle state can be assigned to MT, and has been seen in studies of the dissociation of DMS on Rh(100) [9] and Cu(111) [8]. Figure 2 shows the corresponding C 1s XPS spectra for multilayer, submonolayer at 90, 130, 200 K and RT.…”

“…With regard to the highest temperature, this same state has been seen in atomic S/Rh(100) phase shown below the spectrum of RT phase. It is characterized by a binding energy significantly lower than that of any molecular states, which is investigated by many researches of the decomposition of sulfur-containing molecules on transition metal surfaces [8]. Therefore this component can be obviously identified as atomic S adsorption.…”

Thermal reactions of mercaptoethanol on Cu(100)

“…Studies of x-ray photoelectron spectroscopy have shown that C 2 H 5 SH decomposes to form C 2 H 5 S-on Cu(1 1 1) at 85 K and on Cu(1 1 0) at 100 K at lower coverages [5,11]. In Fig.…”

Chemical State‐specific Surface Structure from Photoemission‐monitored X‐ray Standing Waves

“…On Cu(l 11) it was established some years ago that at room temperature methanethiol not only deprotonates to methanethiolate, CH3S-, but also causes a substantial reconstruction of the surface [15] which has recently been confirmed to involve a pseudo-square (lOO)-like surface layer of Cu atoms on the hexagonal layers of the underlying substrate [16]. S 2p SXPS characterization [17] has shown, however, that at low temperatures the intact thiol may coexist with a distinctly different thiolate species. It was suggested that this may correspond to adsorption on an unreconstructed surface, the reconstruction being kinetically hindered at low temperature.…”