Lysine-modified TiO2 nanotube array for optimizing bioelectricity generation in microbial fuel cells

Abstract As the carrier of electroactive bacteria and part of the electron migration path, the anode is a restricting factor for the power density of microbial fuel cells (MFCs). In this study, carbon-coated TiO 2 nanotube array (TNT/HL) was synthesized by anodization and thermal treatment, for use as anodes in MFCs to promote power production. Due to the sucker structure and the carbon attachment, the TNT/HL anode increased the bacterial loading capacity when exposed under lamplight or natural light. Single-chamber MFCs with the TNT/HL anode achieved a maximum power density of 0.88 W/m 2 , which is much higher than that of MFCs using the common commercial carbon cloth (CC) anode (0.61 W/m 2 ). Further investigation attributed such superior results to the better biocompatibility, enlarged electroactive surface, decreased electric resistance and Tafel slope of the as-prepared TNT/HL anode. This study introduces a promising anode material for MFCs with high conductivity, high current density, and fast extracellular electron transfer (EET).