City Research Online

Abstract

The anodic photoelectrochemical behaviour of flame oxidised iron has been investigated. The transient photo current behaviour has been explained in terms of the creation and subsequent reduction of an oxy-hydroxy intermediate on the electrode’s surface. This has been supported by the results gained by voltammetry and X-ray analysis. The importance of this to the general field of photoelectrochemistry has been considered.

Using the oxy-hydroxy intermediate theory as its basic premise, the anodic electrochemical behaviour of certain transition metal silicates has been studied.

Samples of cobalt, iron and nickel silicates were made by thermal sintering methods and characterised by conductivity measurements and X-ray analysis. Nickel silicate could not be made in a suitably conducting form to be fabricated into an electrode. Iron silicate was found to slowly corrode when polarised anodically. Cobalt silicate was found to have a reasonable performance for the evolution of oxygen. A mechanistic study of cobalt silicate as an electro catalyst for the evolution of oxygen using cyclic voltammetry and potentiostatic pulse techniques has shown that the formation of an oxy-hydroxy intermediate is the essential step in the reaction mechanism.

Unfortunately, the anodic photoelectrochemical behaviour of cobalt silicate has not been studied due to experimental limitations. However, there are grounds to suggest that due to band gap limitations, it will have a poor photoelectrochemical performance.

Publication Type:	Thesis (Doctoral)
Subjects:	Q Science > QD Chemistry
Departments:	School of Science & Technology > School of Science & Technology Doctoral Theses Doctoral Theses

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