Calcined polyaniline–iron composite as a high efficient cathodic catalyst in microbial fuel cells

A new type of carbon–nitrogen–metal catalyst, PANI–Fe–C, was synthesized by calcination process. According to the results of FT-IR and XPS analysis, polyaniline chain was broken by calcination. Small nitrogen-contained molecular fragments were gasified during calcination process, while the remaining nitrogen atoms were enchased in the new produced multiple carbon rings by C–N and CN bonds and performed as the catalytic active sites and the covalent centers for soluble iron components. Calculated from the polarization curves, a maximum power density of 10.17 W/m3 for the MFC with the synthetic catalyst was obtained, which was slightly higher than the MFC with Pt/C catalyst of 9.56 W/m3. All the results obtained in this paper proved that the newly synthetic nitrogen–carbon-metal catalyst would be a potential alternative to the expensive Pt/C catalyst in the field of MFC.