Additive manufactured graphene-based electrodes exhibit beneficial performances in Pseudomonas aeruginosa microbial fuel cells

A commercial polylactic acid/graphene (8 wt%) composite filament was used to additive manufacture (AM) graphene macroelectrodes (AM-G_Ms). The electrode surfaces were characterised and Pseudomonas aeruginosa was utilised as the exoelectrogen. The MFC was optimised using growth kinetic assays, biofilm formation, and quantification of pyocyanin production (via liquid chromatography-mass spectrometry) in conditions that were representative of the batch-fed MFC configuration utilised. Cell potential and bacterial viability was recorded at 0 h, 24 h, 48 h, 72 h, 96 h and 120 h, power density and current density were calculated. There was no significant difference between P. aeruginosa cell proliferation in either media tested. Interestingly, no accumulation of pyocyanin was evident. Additively manufactured electrodes comprised of graphene (AM-G_Ms) were successfully applied in a P. aeruginosa MFC configuration and power outputs (110.74 ± 14.63 μW m^-2) produced were comparable to that of the ‘benchmark’ electrode, carbon cloth (93.49 ± 5.17 μW m^-2). The AM-G_Ms demonstrated power/current outputs similar to that of the carbon cloth electrodes in both anaerobic LB and glucose-based media over 120 h; the AM-G_Ms had no significant detrimental effect on P. aeruginosa viability. This study highlights the potential application of additive manufactured electrodes with the incorporation of nanomaterials (e.g., graphene) as one approach to enhance power outputs.