Green Energy: Power Generation Improvement in Microbial Fuel Cells Using Bio‐Synthesized Polyaniline‐Coated Co 3 O 4 Nanocomposite

Abstract

The sharp increase in global energy consumption in recent years has intensified the focus on replacing traditional nonrenewable energy sources with sustainable and clean energy. Microbial fuel cells (MFCs) are emerging as a viable solution, generating clean energy through the biological breakdown of organic materials. The efficacy of MFCs is highly reliant on the design of their anode electrodes. In this study, a pencil graphite electrode (PGE) modified with the polyaniline‐cobalt oxide (PANI‐Co 3 O 4 ) nanocomposites was made up by the in situ polymerization method, used as the anode for the single‐chamber MFC (SCMFC), and a mixed culture inoculum was used as the biocatalyst. In addition to PANI‐Co 3 O 4 nanocomposites, Co 3 O 4 NPs and PANI were synthesized by combustion and chemical oxidative polymerization methods, respectively, to investigate the performance of MFCs. The desired materials were characterized via UV–Vis, X‐ray diffraction (XRD), FT‐IR, and SEM. MFCs’ performance tests were performed via open‐circuit voltage (OCV) and closed‐circuit voltage (CCV) measurements. OCV measurement of bare PGE, Co 3 O 4 /PGE, PANI/PGE, and PANI‐Co 3 O 4 /PGE electrodes produces maximum results of 238, 394, 565, and 638 mV, respectively. PANI‐Co 3 O 4 /PGE produces a maximum OCV, which was 2.68 times higher than bare PGE. Furthermore, a CCV measurement was performed at external resistance in the range of 100 Ω –100 kΩ. The continuous test on bare PGE, Co 3 O 4 /PGE, PANI/PGE, and PANI‐Co 3 O 4 /PGE was evaluated in glucose‐fed mixed culture‐based SCMFC. The results indicate that PANI‐Co 3 O 4 /PGE can generate maximum power densities up to 413.07 mW/m 2 , which is equivalent to a current density of 2429.56 mA/m 2 . Applying PANI‐Co 3 O 4 nanocomposites to PGEs significantly enhanced the power and current density by 6.78 and 3.92 times, respectively. This study highlights the effectiveness of modified PGE anodes in generating electricity with MFCs. The results demonstrate a potential for using artificial wastewater across various regions to produce green energy from waste.