Effect of electropolymerisation conditions on the permeability of polyphenol films deposited on a vitreous carbon electrode

Abstract

a b s t r a c tPolymeric films were prepared from alkaline (NaOH) phenol aqueous solutions on a vitreous carbon (VC) electrode by potentiostatic or galvanostatic electro-oxidation. Permeation through such films was studied by rotating-disk electrode using the ferricyanide redox couple, and by cyclic voltammetry using phenate ions. The influence of the electropolymerisation controllable parameters such as NaOH and phenol concentrations, potential or current applied, electrosynthesis time, temperature and hydrodynamic conditions (electrode rotation + solution magnetic stirring) on the permeability of these polymeric films was examined. Conditions for the removal of phenol by electropolymerisation are discussed on the basis of the permeability of polyphenol films obtained by electrosynthesis. Permeable films were formed for a concentration of free hydroxyl anion larger of 0.1 M. An increase of the temperature to 85• C favours the formation of highly permeable films, thus avoiding electrode fouling.

Influence of temperature and applied potential on the permeability of polyphenol films prepared on vitreous carbon in acid and alkaline media

“…2)], which helps to reactivate the electrode. Previously we showed [19] that in the polymer layer the pH could become acid under high current density (in Fig. 1b the current reaches 1 mA at 700 mV) forming molecular phenol, and its partition could explain that the height of the oxidation wave beyond the sixth scan exceeded that of the 1st scan [19].…”

“…Recently we studied the removal of phenol from aqueous solution by anodic polymerization [15][16][17][18][19]. Galvanostatic electrolyses conducted on a Ta/b-PbO 2 anode at high current density (200 mA cm -2 ) and high temperature (86°C) showed that 39 % of the starting phenol can be removed as polymer dispersed in the anolyte [15,16].…”

“…The use of high anodic current density avoided anode fouling but unfortunately favoured both oxidation of the polymeric film and oxygen evolution leading to current yields of around 20 % [16]. We have also investigated the electrochemical behavior of phenol on a vitreous carbon electrode by cyclic voltammetry and chronoamperometry in acid [17] and basic [18,19] aqueous solutions at different temperatures in the range 25-85°C. Cyclic voltammetry performed in the potential region of water stability has shown that: (1) phenol oxidation is controlled by adsorption in acid solution and diffusion in basic solution, (2) the vitreous carbon electrode was effectively deactivated vis-àvis phenol oxidation as early as the second potential scan whatever the temperature or pH used and (3) electrode activity was progressively restored over successive potential scans in basic medium only at temperatures of over 60°C while no such reactivation was observed in acid medium even at 85°C.…”

Layered Metal Nanoparticle Structures on Electrodes for Sensing, Switchable Controlled Uptake/Release, and Photo‐electrochemical Applications

“…Furthermore, the synthesis of matrices composed of conducting carbon dots and redox proteins is anticipated to yield effective electrically contacted enzyme electrodes for biosensing and biofuel cell applications. Furthermore, while the electrogenerated bis aniline-crosslinked metal NPs provided the main synthetic method to prepare the matrices, other electroactive molecules (such as pyrrole, [ 65 ] thiophene, [ 66 ] or bisphenol [ 67 ] ) could also act as electroactive polymerizable units. Such new crosslinking units could introduce new functionalities and properties to metal NP matrices.…”

Electropolymerization of N,N'-Diphenylguanidine in Non-Aqueous Aprotic Solvents and Alcohols

“…One of them is size exclusion as the films grown onto the electrode surface make possible the controlled release of molecular or ionic species. For low conductivity layers polyphenols serve as a good example and their transport properties have been widely investigated [25][26][27][28].…”