File(s) under permanent embargo

Reason: Restricted by author. A copy can be supplied under Section 51 (2) of the Australian Copyright Act 1968 by submitting a document delivery request through your library, or by emailing document.delivery@monash.edu

Advanced Electrochemical Techniques for Investigating Electron Transfer Kinetics

thesis
posted on 14.06.2017, 05:22 by Sze-yin Tan
Heterogenous interfacial electron transfer processes are of fundamental and applied importance to electrochemists and are extensively studied by a wide range of electrochemical techniques. This thesis focuses on the development of analysis strategies and electrochemical methodologies for more detailed quantitative investigations of electron transfer kinetics at a plethora of electrode materials, with an emphasis on carbon-based materials. Of interest are the techniques of Fourier-transformed large amplitude alternating current voltammetry (FTACV) and scanning electrochemical microscopy (SECM).

The complementary electrochemical techniques of FTACV and SECM are used for measurements of fast electron transfer to reveal the impact of the complex heterogeneous surface of degenerately-doped polycrystalline boron-doped diamond electrode surfaces compared to conventional electrode materials such as platinum and gold. This part of the work highlights the importance of understanding the influence of measurement technique and further demonstrates how electron transfer at semi-metallic electrodes differ from conventional metallic electrodes.

The oxidation of a ferrocene-derivative at highly oriented pyrolytic graphite is used to demonstrate the effects of reversible reactant adsorption on the SECM response. The high surface area-to-solution volume ratio of nanogap SECM measurements depicts the importance of understanding the impact of such surface effects. Precise quantitative kinetic analysis requires understanding of the mass transport between the SECM probe and electrode surface. Finite element method modelling was used to extensively investigate the effects of electrode reactant processes and the results of the models shed light on important factors that need to be accounted for in quantitative analysis of nanogap voltammetric measurements.

FTACV is further developed as a tool for kinetic selectivity at heterogeneous electrode surfaces. This is achieved by taking advantage of the harmonic-dependent measurement timescale of FTACV to deconvolute a dual-heterogeneity electrochemical response into its individual components. Protocols are developed for this application and demonstrated experimentally using the ruthenium hexamine and ferrocene methanol redox couples.

History

Campus location

Australia

Principal supervisor

Jie Zhang

Additional supervisor 1

Alan M. Bond

Additional supervisor 2

Julie V. Macpherson

Additional supervisor 3

Patrick R. Unwin

Year of Award

2017

Department, School or Centre

Chemistry

Additional Institution or Organisation

University of Warwick

Course

Doctor of Philosophy

Degree Type

Doctorate

Faculty

Faculty of Science