Synthesis and performance of transition metal oxide polypyrrole composite as cathode catalyst in single chamber microbial fuel cell

Abstract

Wastewater treatments are energy-demanding processes, which require around 0.018 newlinekWh for sewage treatment. On the other hand, around 1.5×1011 kWh of energy is stored newlinein the domestic, animal and industrial wastewater in the form of biodegradable organic newlinematter. Microbial fuel cell (MFC) is a green energy conversion technology that newlinecombines wastewater treatment and power generation. MFCs harvest electrons from the newlineoxidation of organic matter with the aid of exoelectrogenic microorganisms (biocatalysts). Noble metal-based catalysts platinum (Pt) was explored as cathode catalysts newlineand it is efficient in improving MFCs performance. Even though platinum has the newlinehighest oxygen capturing capacity, the high cost and poisoning tendency restrict its newlineusage as an electrode catalyst material in MFCs, which is an important research newlineproblem. Therefore, various Pt-free catalysts such as transition metal oxides, carbonmetal derivatives, conducting polymers, and biocatalysts were explored as cathode newlinecatalysts to enhance catalytic activity and improve MFC power output to reduce overall newlinecost. newlineIn this research, the performance of single-chamber membrane MFC (SCMFC) with newlineCarbon cloth as anode and cathode modified with a catalyst such as Polypyrrole/ newlinemolybdenum oxide (Ppy/MoO2), polypyrrole/tungsten oxide (Ppy/WO3), polypyrrole/ newlinetitanium oxide (Ppy/TiO2) and granular activated carbon derived from groundnut shell newlinewere analyzed. Physical characterization of catalyst viz. X-Ray diffraction (XRD), newlineFourier transform infrared spectroscopy (FTIR), Field-emission scanning electron newlinemicroscopy (FE-SEM), Brunauer Emmett Teller (BET), X-ray photoelectron newlinespectroscopy (XPS) and Energy dispersive X-Ray spectroscopy (EDS), were performed newlineto demonstrate the unique nature and purity of the material. Electrochemical newlinecharacterizations like cyclic voltammetry (CV) and electron impedance spectroscopy newline(EIS) were performed to confirm the high charge transfer capacity and catalytic activity.