Fe3O4@nitrogen doped bread derived porous carbon free-standing anode enhancing electricity generation and azo dye decolorization of microbial fuel cell.

Anode material is a core component to determine the actual application performance of microbial fuel cells (MFCs). Herein, Fe3O4@N-doped bread derived porous carbon (Fe3O4@N-BMC) was prepared as a free-standing anode for MFC device. The Fe3O4 nanoparticles were beneficial to enhancing the microbial metabolic decomposition ability and improving the extracellular electron transfer efficiency. The N-doped surfaces ensured high conductivity and hydrophilicity. The hydrophilic porous surface structure could promote rapid adhesion of microorganisms. The porous structure was beneficial for facilitating microorganisms to make full use of internal space. The novel physical structure and chemical composition enabled the formation of a thick biofilm on the free-standing anode with good metabolic activity, thereby excellent electricity generation performance and efficient wastewater treatment efficiency. The Fe3O4@N-BMC MFC presented a high output voltage (0.589 ± 0.007 V) and a large maximum power density (1083 ± 48 mW m-2), which were higher than those of carbon cloth MFC (0.532 ± 0.001 V and 530 ± 7 mW m-2). The exceptional dye wastewater treatment performance was revealed by the decolorization efficiency of 93.88 ± 2.29% at 36 h and chemical oxygen demand removal efficiency of 81.78 ± 0.04% in the first cycle. The fabricated Fe3O4@N-BMC is a potential free-standing anode for MFC to recover the electrical energy from dye wastewater treatment process.