An ultramicroelectrode study of ferrocene diffusion and heterogeneous electron transfer rate in polyelectrolyte

✍ Scribed by Huafang Zhou; Shaojun Dong

• Book ID: 104115051
• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 619 KB
• Volume: 42
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/s0013-4686(96)00380-5

✦ Synopsis

Steady-state voltammograms at a microdisk electrode are used to measure the diffusion coefficient (D) and standard heterogeneous rate constant (k,) of ferrocene in polyelectrolyte PEG.MClOd. The diffusion coefficient and standard heterogeneous rate constant of ferrocene are both smaller in polymer solvents than in monomeric solvents. The D and k, of ferrocene have been estimated in PEG containing different concentrations and cations of supporting electrolytes, and the dependencies of D and k, on temperature have been observed. These results show that the D and k, of ferrocene increase with increasing temperature in polyelectrolyte, and with increasing cation radius of supporting electrolyte, eg D and k, increase in the order B&NC104 > NaC104 > LiC104. On the other hand, D and k, increase with decreasing concentration of supporting electrolyte. The dependence of the half-wave potential (El,z) on the concentration of the supporting electrolyte is also observed. E1,2 shifts in the negative direction as the concentration of supporting electrolyte increases.