Underpotential (UPD) deposition of sulfur from Na2S solution in 0.1MNaOH was studied on Ag(100) and Ag(110) using in situ scanning tunneling microscopy (STM). The cyclic voltammogram on Ag(100) presents two broad peaks, whereas three partial overlapping peaks and a sharper one are observed on Ag(110). STM measurements carried out during the whole UPD process show that progressively more compact structures are formed as the applied potential is scanned toward more positive potentials. More precisely, p(2x2), c(2x6), and c(2x2) were found on Ag(100) at E = -1.25, -1.0, and -0.9 V, respectively. Less definite conclusions can be drawn for the structures of S overlayers on Ag(110). However, the experimental findings are consistent with an incomplete p(2x1) at potentials preceding the sharp peak, and with a c(2x2) structure at E=-0.9 V vs Ag/AgCl, KClsat. The coverage values calculated on the basis of the hypothesized structures have been compared with the values obtained from chronocoulometric measurements at the most positive potentials investigated. Thus, the experimental coverage è=0.5 coincides with the coverage calculated for the c(2x2) structure found on Ag(110) at E = -0.9 V by STM, whereas the experimental coverage è = 0.42 suggests that a mixture of structures c(2x6) and c(2x2) is formed on Ag(100).

In Situ STM investigation of Sulfur Oxidative Underpotential Deposition on Ag(100) and Ag(110) / E. Lastraioli; F. Loglio; M. Cavallini; F.C. Simeone; M. Innocenti; F. Carlà; M.L. Foresti.. - In: LANGMUIR. - ISSN 0743-7463. - STAMPA. - 26(22):(2010), pp. 17679-17685. [10.1021/la103030b]

In Situ STM investigation of Sulfur Oxidative Underpotential Deposition on Ag(100) and Ag(110)

LASTRAIOLI, ELISA;LOGLIO, FRANCESCA;INNOCENTI, MASSIMO;FORESTI, MARIA LUISA
2010

Abstract

Underpotential (UPD) deposition of sulfur from Na2S solution in 0.1MNaOH was studied on Ag(100) and Ag(110) using in situ scanning tunneling microscopy (STM). The cyclic voltammogram on Ag(100) presents two broad peaks, whereas three partial overlapping peaks and a sharper one are observed on Ag(110). STM measurements carried out during the whole UPD process show that progressively more compact structures are formed as the applied potential is scanned toward more positive potentials. More precisely, p(2x2), c(2x6), and c(2x2) were found on Ag(100) at E = -1.25, -1.0, and -0.9 V, respectively. Less definite conclusions can be drawn for the structures of S overlayers on Ag(110). However, the experimental findings are consistent with an incomplete p(2x1) at potentials preceding the sharp peak, and with a c(2x2) structure at E=-0.9 V vs Ag/AgCl, KClsat. The coverage values calculated on the basis of the hypothesized structures have been compared with the values obtained from chronocoulometric measurements at the most positive potentials investigated. Thus, the experimental coverage è=0.5 coincides with the coverage calculated for the c(2x2) structure found on Ag(110) at E = -0.9 V by STM, whereas the experimental coverage è = 0.42 suggests that a mixture of structures c(2x6) and c(2x2) is formed on Ag(100).
2010
26(22)
17679
17685
E. Lastraioli; F. Loglio; M. Cavallini; F.C. Simeone; M. Innocenti; F. Carlà; M.L. Foresti.
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Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/597603
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