Photosynthetic Microbial Fuel Cell (p-MFC) research aims to develop devices containing photosynthetic micro-organisms to produce electricity. Micro-organisms within the device photosynthesise carbohydrates under illumination, and produce reductive equivalents (excess electrons) from both carbohydrate production and the subsequent carbohydrate break down. Redox mediators are utilised to shuttle electrons between the organism and the electrode. The mediator is reduced by the micro-organism and subsequently re-oxidised at the electrode. However this technology is in its early stages and extensive research is required for p-MFC devices to become economically viable.A basic p-MFC device containing a potassium ferricyanide mediator and the algae Chlorella vulgaris was assembled and tested. From these initial experiments it was realised that much more work was required to characterise cell and redox mediator activities occurring within the device. There is very little p-MFC literature dealing with cellular interaction with redox mediators, but without this knowledge the output of complete p-MFC devices can not be fully understood. This thesis presents research into the reduction of redox mediators by the micro-organisms, including rates of mediator reduction and factors affecting the rate. Both electrochemical and non-electrochemical techniques are used and results compared. Additionally, cellular effects relating to the presence of the mediator are studied; crucial to provide limits within which p-MFCs must be used. After basic characterisation, this thesis presents work into the optimisation of the basic p-MFC. Different redox mediators, photosynthetic species and anodic materials are investigated. Importantly, it is only through fundamental characterization to improve understanding that p-MFCs can be optimised.
|Date of Award||7 Mar 2012|
|Supervisor||Petra Cameron (Supervisor), Laurie Peter (Supervisor) & Andrew Dent (Supervisor)|
- bio-photo-voltaic cells
- photosynthetic microbial fuel cells