Miniaturized Electrodes Based on Electrospun Carbon Nanofibers

S. Chigome, N. Torto
Rhodes University, ZA

Keywords: electrospun carbon nanofibers, miniaturized electrodes, carbonaceous blend, anodic bioelectrocatalysis

Summary:

Electrospun carbon nanofibers obtained from polyacrylonitrile (PAN) and PAN blends with either activated carbon (PAN-AC) or graphite (PAN-GR) were tested as anodes using Shewanella oneidensis MR-1. Extensive physico-chemical and electrochemical characterization confirmed their formation, their fibrous and porous nature, and their suitability as electrodes. N2 adsorption measurements revealed high specific surface area (229.8, 415.8 and 485.2 m2g-1) and porosity (0.142, 0.202 and 0.239 cm3g-1) for PAN, PAN-AC and PAN-GR respectively. The chronoamperometric measurements showed a significant decrease in start-up time and more than a 10-fold increase in the generation of current with these electrodes (115, 139 and 155 μAcm-2 for PAN, PAN-AC and PAN-GR respectively) compared to the conventional graphite electrode (11.5 μAcm-2). The fibrous and porous nature of such materials presumably provides the habitat for maximum growth of bacteria while permitting an efficient substrate supply and product exit from it. These results suggest that blending such carbon nanofiber precursors as PAN with conductive and carbonaceous materials can be a strategy for enhancing electrochemical performance of miniaturized electrodes.