An investigation of electrochemical contact processes for silver-wire|glassy carbon and silver-coated cotton textile|glassy carbon

Abstract

Silver-coated cotton textile discs in contact to glassy carbon exhibit environment dependent electrochemical contact reactivity.

Redox reactivity at silver microparticle—glassy carbon contacts under a coating of polymer of intrinsic microporosity (PIM)

“…Figure 3a shows voltammograms with an oxidation response at 0.26 V vs. SCE. Silver has been reported to undergo oxidation (anodic dissolution) in neutral aqueous phosphate buffer media to switch from Ag(0) to Ag(I) accompanied by formation of poorly soluble phosphate films [11,22,23] (see Eq. 1).…”

“…Due to the small size of these nanoparticles (and the appropriate choice of reaction conditions) complete/quantitative conversion of silver to soluble or insoluble species is usually possible [10]. In contrast, for macroscopic silver samples, for example a silver wire or silvercoated textiles, in contact to a glassy carbon electrode surface [11], more complex behaviour has been reported with incomplete conversion and formation of an electrically insulating layer between silver metal and electrode surface. The electrical contact of metallic silver to the underlying glassy carbon electrode has been shown to be broken during oxidation when an insulating film is produced.…”

“…The electrical contact of metallic silver to the underlying glassy carbon electrode has been shown to be broken during oxidation when an insulating film is produced. As a result, only a small amount of the available silver was oxidised [11]. The back-reduction to metallic silver was suggested to be associated with nucleation of silver metal on glassy carbon and a Bre-connection^from glassy carbon to the metallic silver-coated textile.…”

“…In this study, silver microparticles are investigated at glassy carbon electrode surfaces and when immersed into aqueous phosphate buffer solution. During oxidation, silver microparticles are shown to only react partially (similar to silver wire in contact to glassy carbon [11]) due to surface coating with an insulating silver phosphate film. The process is chemically reversible, and after back reduction, the silver microparticles remain at the electrode surface (protected by a PIM-EA-TB film).…”