Congratulations to Graham for passing his viva on Friday!
Parameter recovery in AC solution-phase voltammetry and a consideration of some issues arising when applied to surface-confined reactions
A major problem in the quantitative analysis of AC voltammetric data has been the variance in results between laboratories, often resulting from a reliance on “heuristic” methods of parameter estimation that are strongly dependent on the choices of the operator. In this thesis, an automatic method for parameter estimation will be tested in the context of experiments involving electron-transfer processes in solution-phase. It will be shown that this automatic method produces parameter estimates consistent with those from other methods and the literature in the case of the ferri-/ferrocyanide couple, and is able to explain inconsistency in published values of the rate parameter for the ferrocene/ferrocenium couple. When a coupled homogeneous reaction is considered in a theoretical study, parameter recovery is achieved with a higher degree of accuracy when simulated data resulting from a high frequency AC voltammetry waveform are used.
When surface-confined reactions are considered, heterogeneity in the rate constant and formal potential make parameter estimation more challenging. In the final study, a method for incorporating these “dispersion” effects into voltammetric simulations is presented, and for the first time, a quantitive theoretical study of the impact of dispersion on measured current is undertaken.
You can find papers arising from his work here:
- G. P. Morris, A. N. Simonov, E. A. Mashkina, R. Bordas, K. Gillow, R. E. Baker, D. J. Gavaghan and A. M. Bond (2013). A comparison of fully automated methods of data analysis and computer assisted heuristic methods in an electrode kinetic study of the pathologically variable [Fe(CN)6]3- /4- process by AC voltammetry. Anal. Chem. 85(24):11780–11787. DOI
- A. N. Simonov, G. P. Morris, E. A. Mashkina, B. Bethwaite, K. Gillow, R. E. Baker, D. J. Gavaghan and A. M. Bond (2014). Inappropriate use of the quasi-reversible electrode kinetic model in simulation-experiment comparisons of voltammetric processes that approach the reversible limit. To appear in Anal. Chem. DOI