Anodes for glucose fuel cells based on carbonized nanofibers with embedded carbon nanotubes

Electrodes made of carbonized polyacrylonitryle (cPAN) nanofibers, with and without embedded multiwall carbon nanotubes (MWCNTs) were fabricated by the electrospinning (ES) process and evaluated as anodes in glucose fuel cell (FC) application. The effect of several processing and structural characteristics, such as the presence of MWCNTs, polymer concentration in the ES solution and silver electroless plating on FC performance were measured. The carbon electrodes were successful as anodes showing significant activity even without additional silver catalyst, with noticeable improvement by the incorporation of MWCNTs. The orientation of graphitic layers along the fiber axis and the coherence of layer packing were shown to be important for enhanced electrode activity. The maximal values of open circuit voltage (OCV) and peak of power density (PP_D) of unmetalized electrodes, 0.4 V and 30 μW/cm² respectively, were found to be for composite cPAN/CNT electrode. Electroless silver metallization of the carbon nanofiber electrodes leads to much better FC performance. Maximal values of OCV and PP_D of silvered carbon electrodes were measured to be about 0.9 V and 400 μW/cm², respectively. Thus, carbonized nanofibers with embedded MWCNTs may form a good basis for glucose FC anodes, but better metallization and cell-configuration allowing proper mixing are required.