Formation of negative oxidation states of platinum and gold in redox ionic liquid: Electrochemical evidence |
| |
Authors: | Jalal Ghilane Olivier Fontaine Pascal Martin Jean-Christophe Lacroix Hyacinthe Randriamahazaka |
| |
Affiliation: | aInterfaces, Traitements, Organisation et Dynamique des Systèmes, Université Paris 7-Denis Diderot, CNRS UMR 7086, 1 rue Guy de la Brosse, 75005 Paris, France |
| |
Abstract: | The electrochemical reduction of noble metal electrodes in the presence of redox ionic liquid, 1-ferrocenylethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [FcEMIM][TFSI], was investigated by cyclic voltammetry. Our experiments suggest the formation of metal with negative oxidation states, in the cases of platinum and gold electrodes [Mn−, FcEMIM+]. By analogy with the previous work, the formation of these phases is concomitant with the insertion of the supporting electrolyte; which correspond in our experimental condition to the redox cation of the ionic liquid. As an exciting result, the electrochemical investigations of the reduced electrode in electrolytic solution, containing solvent and supporting electrolyte, evidence the presence of the ferrocene groups at the electrode surface. Moreover, the reduced electrode exhibits the presence of the ferrocene even after, contact with air, after ultrasound, and after physical polishing, highlighting the large stability of this organo-metallic phases formed in this media. The AFM investigations demonstrate the morphological change of the platinum surface after the reduction process. Finally, our works bring a formal electrochemical proof of the presence of the ionic liquid cation inside the electrode material after the cathodic treatment in this media. |
| |
Keywords: | Surface modification Noble metal Platinum and gold Cyclic voltammetry Redox ionic liquid |
本文献已被 ScienceDirect 等数据库收录! |
|