A SERS Investigation of Cyanide Adsorption and Reactivity during the Electrodeposition of Gold, Silver, and Copper from Aqueous Cyanocomplexes Solutions

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• 作者：Benedetto Bozzini ; Lucia D'Urzo ; Claudio Mele ; Vincenzo Romanello
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：April 24, 2008
• 年：2008
• 卷：112
• 期：16
• 页码：6352 - 6358
• 全文大小：142K
• 年卷期：v.112,no.16(April 24, 2008)
• ISSN：1932-7455

文摘

In this paper, we report on the reactivity of adsorbed cyanide deriving from ligand release during metalelectrodeposition from cyanocomplex solutions of Au(I), Au(III), Ag(I), and Cu(I) in H₂O and D₂O. WhenCN^- is adsorbed at cathodic potentials in excess of the HER threshold, metal-dependent reactivity can bedetected by SERS. Finite surface coverages with adsorbed CN^- at such cathodic potentials can be obtainedonly if CN^- is delivered directly to the cathode surface as by decomplexing of the cyanocomplexes of themetals undergoing cathodic reduction. In Au(I) and Au(III) baths, Au-CN^- reacts with hydrogen-relatedspecies to yield adsorbed CH₂=NH and CH₃-NH₂. Similarly, in Ag(I) baths, Ag-CN^- reacts topolycyanogens. No reactivity of Cu-CN^- was found, under otherwise identical conditions. Our conclusionsare supported also by dedicated DFT molecular computations.