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A (surface‐enhanced) Raman spectroscopic study of the adsorption of S 2 O 3 2 − and SCN − on a silver deposit
Author(s) -
Gonnissen D.,
Langenaeker W.,
Hubin A.,
Geerlings P.
Publication year - 1998
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/(sici)1097-4555(199812)29:12<1031::aid-jrs314>3.0.co;2-4
Subject(s) - adsorption , raman spectroscopy , chemistry , electrochemistry , electrode , surface enhanced raman spectroscopy , substrate (aquarium) , electrode potential , analytical chemistry (journal) , inorganic chemistry , crystallography , raman scattering , organic chemistry , physics , oceanography , optics , geology
The study of the adsorption behaviour of SCN ‐ andS 2 O 3 2‐ at a silver substratecontributes substantially to an improved insight into theelectrochemical formation of a silver image in photographicdevelopment processes. (Surface‐enhanced) Raman(SER) spectroscopy and quantum chemical calculations revealthe existence of an S coordination for both species with Ag, forming1,1‐AgSCN and1,1‐AgS 2 O 3 ‐ surfacecomplexes, respectively, at the Ag electrode surface. At an electrodepotential of ‐0.1 V vs . SCE, the SER peaks of adsorbedSCN ‐ intensify when the bulk concentration isincreased from 1×10 ‐4 to6×10 ‐3 M , whereas those of adsorbedS 2 O 3 2‐ are already measurableat a bulk concentration of 1×10 ‐5 M and saturate at 3×10 ‐4 M . In bothcases, the AgS bond weakens when the potential is lowered from‐0.1 to ‐0.5 V vs . SCE. The correspondencebetween SER and capacity measurements reveals that a decrease inpotential also causes a decrease in the AgSCN surface concentration.The 1,1‐AgS 2 O 3 ‐ complexeven disappears at potentials below ‐0.2 V vs . SCE. Theformation of a physical adsorption state at lower potentials issuggested. © 1998 John Wiley & Sons, Ltd.