Electrochemical behavior of o-chloranil in aqueous solution at an activated glassy carbon electrode

✍ Scribed by Hamid R. Zare; Marzieh Eslami; Mansoor Namazian

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 427 KB
• Volume: 56
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2010.11.100

✦ Synopsis

A study has been conducted on the effect of specific adsorption of o-chloranil, OCA, at an activated glassy carbon electrode, AGCE, surface on its electrochemical behavior in an aqueous solution. The voltammetric responses of OCA at an AGCE show an anodic prepeak and a cathodic postpeak other than the diffusion main couple in weak acidic and neutral pHs. The anodic prepeak and the cathodic postpeak are ascribed to specific adsorption of OCA. The pK a value of the adsorbed redox couple of OCA at an AGCE is at least by 4 and 2 pK a units higher than those of the free redox couple in solution at bare and activated glassy carbon electrodes, respectively. The slop of (I p ) ads /(I p ) diff ratio versus 1/2 for the cathodic and anodic peaks indicates a stronger adsorption of OCA at AGCE in comparison with OCAH 2 . The effects of OCA concentration on its adsorption behavior and applied potential on anodic adsorption of OCA at AGCE have been studied and the surface coverage of OCA ( OCA ) has been calculated.