Effects of surface functional groups of coal-tar-pitch-derived nanoporous carbon anodes on microbial fuel cell performance

Coal tar pitch, the residue generated from distillation of coal tar, is cheap, abundant, and carbon enriched. This paper evaluates the effects of the surface modification of coal-tar pitch-derived nanoporous carbons (NPCs) as anode materials on the performance of Escherichia coli (E. coli)-based microbial fuel cells (MFCs) for the first time. The coal-tar pitch precursors are heated under N₂ to 450 ^°C (450O) and 750 ^°C (750X) to obtain NPCs with different concentrations of oxygen-containing functional groups. 750X is, thereafter, doped with nitrogen atoms to generate a nitrogen-doped NPCs (750N). More biofilm is formed on the 750N anode than the 750X or 450O anode because of the higher electrical conductivity and biocompatibility of 750N. As a result, a higher power output of MFC is obtained when the 750N anode is used. The maximum power density of 750N is 3772 mW m⁻², while that of 750X and 450O are 2876 mW m⁻² and 3562 mW m⁻², respectively, demonstrating that 750N is a potential sustainable anode material for high-performance MFC applications.