Tuning electrospinning hierarchically porous nanowires anode for enhanced bioelectrocatalysis in microbial fuel cells

Pore structure plays critical roles in electrode kinetics but very challenging to tailor porous nanowires with rationally distributed pore sizes in a bioelectrochemical system. Herein a hierarchically porous nanowires-material is delicately tuned for an optimal pore structure by adjusting the weight percentage of SiO₂-hard template in an electrospinning precursor solution. The as-prepared optimal electrospinning nanowires further used as an anode of microbial fuel cells (MFCs), delivering a maximum output power density of 1,407.42 mW·m⁻² with 4.24 and 10 times higher than that of the non-porous fiber and carbon cloth anode, respectively. The great enhancement is attributed to the rational pore structure which offers the largest surface area while the rich-mesopores well match with the size of electron mediators for a high density of catalytic centers. This work provides thoughtful insights to design of hierarchical porous electrode for high-performance MFCs and other bioelectrochemical system devices.