Analysis of pyridine-2-carbaldehyde thiosemicarbazone as an anti-biofouling cathodic agent in microbial fuel cell

Microbial fuel cells (MFCs) have gained attention due to their applications in the energy and environmental sectors. However, several challenges must be addressed in order to operate MFCs in the real world. Cathode biofouling, which poses mass transfer limitations, is a major factor behind poor performance of MFCs. In this study, a water-insoluble pyridine-2-carbaldehyde thiosemicarbazone (PCT) was synthesized and its efficiency as anti-biofouling agent in the cathode of a multi-criteria MFC (MCMFC) was tested. For the application of PCT, graphite dust and MnO₂ nanotubes (NTs) were used as conducting support and oxygen reduction reaction (ORR) catalyst. When the concentration of PCT on the cathode was increased, an increase in the power generation was observed. The PCT loading of 0.05, 0.1, 0.2, and 0.4 mg/cm² on graphite-MnO₂-NTs cathode, resulted in maximum power density of 356.8, 390.93, 418.77, and 434.2 mW/m², respectively. Half-cell polarization and electrochemical impedance study revealed that the mechanically mixed PCT-MnO₂-NTs/graphite dust composite has a higher ORR activity than MnO₂-NTs/graphite dust composite, implying that the dispersion of PCT on the cathode surface improves its catalytic activity, possibly due to the antibacterial activity of PCT. PCT played an important role in improved energy recovery and could be applied as an efficient antifouling agent and cathode catalyst for the MFC. KEY POINTS: • Water-insoluble pyridine-2-carbaldehyde thiosemicarbazone (PCT) was synthesized. • A multi-criteria microbial fuel cell (MCMFC) was designed. • PCT was used as an oxygen reduction reaction catalyst in MCMFC.