Structure design of 3D hierarchical porous anode for high performance microbial fuel cells: From macro-to micro-scale

Microbial fuel cell (MFC) is a promising technology that can simultaneously achieve wastewater treatment and energy recovery, but its low power output cannot satisfy the practical application. The performance of bioanodes, determined by the materials and structure, significantly affects the power output of MFCs. Herein, a designing approach is proposed to obtain high-performance bioanodes with the optimized macro- and microstructural using three-dimensional (3D) printing technology and electropolymerization. Through adjusting the distribution of large pores (i.e., 0.7 mm) and small pores (i.e., 0.4 mm) in 3D electrodes, the bioanode possesses an optimized macrostructure with large specific surface areas for the attachment of electroactive bacteria and sufficient mass transfer for bioelectrochemical reaction. Then the surface of electrode is further modified with 3D polypyrrole/ graphene oxide (PPy/GO) microstructure to facilitate the formation of biofilm and the electron transfer at the biological/inorganic interfaces. Consequently, the bioanode with optimized macro- and microstructure achieves a high power density of 22.4 +/- 0.6 W/m2, which is 18.7 times higher than that of commercial carbon felt electrode. This study brings new insights to design bioanodes in MFCs, providing a promising practical prospect.

Automated summary

A designing approach using 3D printing technology and electropolymerization was proposed to obtain high-performance bioanodes for microbial fuel cells (MFCs), significantly improving power output and showing promising practical prospects. The optimized macro- and microstructure of the bioanode achieved a high power density of 22.4 +/- 0.6 W/m2, 18.7 times higher than that of commercial carbon felt electrode, indicating a new insight for bioanode design in MFCs.