Treatment of carbon fiber brush anodes for improving power generation in air-cathode microbial fuel cells

Carbon brush electrodes have been used to provide high surface areas for bacterial growth and high power densities in microbial fuel cells (MFCs). Three different treatment methods were first used to examine the power generation of carbon fiber (CF) brushes. It was proven that heat treatment (CF-) can improve power production to 1280 mW m^-2, which was 25.4% larger than the untreated control (CF-C, 1020 mW m^-2). Different heat treatment temperature was applied to carbon fiber and different power generated. XPS and NMR analysis of the treated and untreated anode materials indicated that power increases were related to higher N1s/C1s ratios and a lower C-O composition. These findings demonstrate efficient and simple methods for improving power generation, and provide insight into reasons for improving performance that may help to further increase power through other carbon fiber modifications.