Sulfur Interaction with Cu(100) and Cu(111) Surfaces: A Photoemission Study

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• 作者：Juanjuan Jia ; Azzedine Bendounan ; Karine Chaouchi ; Vladimir A. Esaulov
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：October 23, 2014
• 年：2014
• 卷：118
• 期：42
• 页码：24583-24590
• 全文大小：464K
• ISSN：1932-7455

文摘

Results of a high-resolution synchrotron photoemission study of sulfur adsorption on Cu(100) and Cu(111) surfaces are reported. Sulfur adsorption was performed by immersion of pristine samples into aqueous Na₂S, which provokes strong sulfidation of copper. Annealing leads to partial elimination of S and progressive formation of well-ordered surface sulfur phases followed here by LEED. This translates into sizable Cu 2p core level binding energy (CLBE) shifts as well as changes in the S 2p binding energies. For Cu(111) we see evolution at the higher temperature to the (鈭? 脳 鈭?)R19.1掳 phase as identified by LEED, with a S 2p_3/2 binding energy of 161.45 eV. An intermediate phase with an S 2p_3/2, binding energy of 161.15 eV appears at lower temperatures. For Cu(100) at 300 掳C we see the appearance of the known 0.47 ML S coverage (鈭?7 脳 鈭?7)R14掳 structure, with S 2p_3/2 CLBE of 161.15, 161.62, and 162.10 eV. At higher temperatures some S atom loss occurs, and we observe a p(2 脳 2)-S phase, with S 2p_3/2 CLBE of 161.05 eV and a smaller component at 164.45 eV that could correspond to local c(4 脳 2) domain boundaries as identified in earlier studies. The core level binding energies of Cu 2p are reported along with valence band characteristics.