Improving the performance of graphite anode in a Microbial Fuel Cell via PANI encapsulated α-MnO2 composite modification for efficient power generation and methyl red removal

In this work, the biosynthesized alpha-MnO2 nanoparticles (NPs) encapsulated with a polyaniline (PANI) conducting matrix to form alpha-MnO2/PANI hybrid composite were fabricated by the in situ polymerization method. The prepared material was characterized through UV-Vis spectroscopy, XRD, FTIR, TGA-DTA, DSC, SEM-EDX, cyclic voltammetry, and impedance spectroscopy. A double chambered microbial fuel cell (MFC) cell set up with the pencil graphite electrode (PGE) anode modified by alpha-MnO2/PANI nanocomposite was employed for simultaneous methyl red (MR) decolorization and bioelectricity generation. The influence of MR concentration and its co-substrate glucose under optimum temperature conditions (28 +/- 2 degrees C) was studied. The high decolorization efficiency (DE) of 95.57 +/- 2.26%, maximum power density of 820.02 +/- 7.86 mW m(-2), current density of 1990.34 mA m(-2) with a chemical oxygen demand (COD) of 74.59 +/- 1.57% were achieved using alpha-MnO2/PANI modified PGE. This was increased by 12.47 times compared to unmodified PGE due to the better surface structure modification of PGE by binary composites. So, the nanocomposite modified anode is capable of maximizing MR decolorization in MFC. As a result, this study provided a future path for renewable energy production and azo dye decolorization from wastewater effluents.