Activated nitrogen-doped ordered porous carbon as advanced anode for high-performance microbial fuel cells

Abstract

Microbial fuel cells (MFCs) emerge as an active research topic in environmental engineering as they can effectively recover energy by degrading organic pollutants. However, the low power output impedes their further development. In this study, natural cassava straws are used as a carbon source to prepare activated nitrogen-doped porous carbon via a facile electrochemical activation method. Scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transformer infrared (FT-IR) spectra, and nitrogen adsorption-desorption experiments are conducted to characterize the as-prepared carbon materials. The results indicate that the electrochemical treatment endows the carbon substrate with a large pore volume and some nitrogen and oxygen dopants, which dramatically enhance its electrochemical performance. Consequently, the maximum power density of the MFC with the three-dimensional porous carbon anode prepared under an electrical current of 5 mA reaches 2204.5±29 W m−3, which is 1.90 and 2.76 times of the power densities of the MFCs with the unmodified anode (1155.6±41W m−3) and a commercial graphitic tube anode (808.24 W m−3), respectively. This study provides a meaningful reference for the development of biomass-based, highly efficient, three-dimensional carbon anodes.