Conductive Polymer-Bridged Direct Electron Transfer

2 Conductive Polymer-Bridged Direct Electron Transfer 

One efficient engineering strategy to improve the EET is to use the bridging aetion of conductive polymers. Such polymers can deliver electrons directly from cell to cell/electrode, which is similar to the natural direct electron transfer (DET) between cells and the electrode. 

Therefore, it can be concluded that the redox proteins (c-type cytochrome etc.) and electrodes comprise the main part of DET. The increased contact of the redox proteins (c-type cytochrome etc.) and electrodes would be helpful to DET, thereby influencing the MFC efficiency. Evidence has revealed that some conductive polymers could act as electrical wiring between cells and anodes (Table 5.2). 

Poly(l-vinylimidazole)i2-[Os-(4,4 -dimethyl-2,2 -bipyridyl)2Cl2] and poly(vi-nylpyridine)-[Os-(Af,A -methylated-2,2 -biimidazole)3] were reported for their efficient capability of mediating electrons transfer between bacterial cells to electrodes. With S. oneidensis, the osmium redox polymer modified anode showed a 4-fold increase in current generation and a significant decrease in the start-up time for electrocatalysis. Using an anode modified with electropolymerized polypyrrole, a dramatic improvement in energy output was noticed in the MFCs. MFCs with a polypyrrole/ anthraquinone-2,6-disulfonic disodium salt (PPy/AQDS)-modified anode 

Original Anode Anode after modification Cathode 

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