Experiments

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Copyright © 2009 Southampton Electrochemistry Group

Last modified: 13 January 2009

The Southampton Electrochemistry - SummerSchool

Instrumental Methods in Electrochemistry

5th - 10th July 2009

Hands on practicals with a choice of 5 out of 12 experiments using state of the art PC driven instruments from leading manufacturers.

 

Provisional

 

1. Cyclic Voltammetry (I) - Surface Reactions: Cyclic voltammetry will be used to examine surface changes at electrodes. Adsorption and oxide formation on gold and platinum, as well as the redox cycling of polyaniline, will be considered.

2. Cyclic Voltammetry (II) - Solution Reactions: Cyclic voltammetric measurements provide a simple diagnostic method for the preliminary study of homogeneous reactions coupled to redox processes. In this experiment, the electrochemistry of ferrocene monocarboxylic acid is first investigated, followed by a study of its use as a homogeneous mediation for the oxidation of glucose oxidase and enzyme used in blood glucose measurement.

3. Numerical simulations of electrochemical processes: This experiment uses a commercial simulation package (DigiSim) to simulate both simple electron transfer reactions and complex mechanisms with coupled homogeneous chemical reaction. The aim is to investigate how the rates of electron transfer and chemical kinetics alter the voltammetric behaviour at macro and microelectrodes. In the final part of the experiment, the simulation package is used to determine the mechanism for a reaction based on the analysis of experimental data provided. The experiment illustrates the underlying principles of voltammetry and the relationship between the concentration profiles and the measured currents.

4. Fuel cells characterisation: Half cell testing of PEM fuel cell electrodes: In this experiment a Nafion bound PEM fuel cell electrode will be made from the ink using a spreading method. The electrochemically active area of the electrode will be determined using carbon monoxide oxidation. The activity of the electrode for methanol oxidation will be assessed from the polarisation curves.

5. Rotating Disc Electrode: The rotating disc electrode allows control of the mass transport to the electrode. The rotation dependence of the reduction of Cu2+ to Cu+ and Cu0 will be investigated.

6. Rotating Ring Disc Electrode: The configuration of the two working electrodes in a RRDE allows the detection at the ring of intermediates produced at the disc. The intermediate produced during the reduction of O2 at platinum will be investigated.

7. Microelectrodes: This experiment highlights some of microelectrodes' properties: high rate of steady state mass transport, reduced iR drop distortion and improved discrimination against charging current. A range of microdiscs with diameters < 100 µm is used to study the oxidation of ferrocene in acetonitrile in presence and absence of supporting electrolyte by means of linear sweep voltammetry and fast cyclic voltammetry.

8. A.C. Impedance Spectroscopy: The impedance of a simple redox system (ferro/ferricyanide) will be investigated to illustrate the technique and the interpretation of the results. The effect of reducing the supporting cation concentration will be explored.

9. Characterisation of Electrochemical Materials: Electronic conductivity, ionic conductivity, diffusion coefficient and pseudo-capacitance are important parameters for the evaluation of electrochemical materials for many applications. This experiment will investigate the determination of these values by impedance and time domain techniques.

10. Factors Determining Experimental Response: Electrochemistry relies, in most cases, on the measurement of either the current or the potential recorded at an electrode as a function of other physical parameters of the system. These measurements are subject to practical considerations, some of which will be highlighted in this experiment. Factors such as equipment response, uncompensated resistance, cell design and experiment design are demonstrated and simple counteractive measures suggested.

11. Spectroelectrochemistry: In this experiment, we employ a UV-Vis diode array spectrometer interfaced to a potentiostat to monitor spectrophotometric changes of electroactive species with electrode potential. Specifically poly(aniline) (electrode bound) or 5,6-diaminouracil (solution species) will be studied at an optically transparent electrode (OTE, e.g. indium doped tin oxide).

12. Electrodeposition of metals and Scanning Electron Microscopy: This experiment considers various aspects of metal electrodeposition. Emphasis is given to the experimental conditions and electrochemical techniques available to study the deposition. The relationship between platting conditions and the deposit morphology will be investigated with a scanning electron microscope. 

 

Download the Experiment Choice Form, fill it in and Post / Fax / Email it to

 

 

Guy Denuault

 

Fax:      +44 (0) 23 80 59 37 81

Email:    gd@soton.ac.uk

 

Postal address:

             School of Chemistry, University of Southampton,

             Highfield, Southampton, SO17 1BJ, UK