Electrochemically Prepared Manganese Oxide as a Cathode Material for a Microbial Fuel Cell

Abstract

This work describes the construction of a mediatorless microbial fuel cell (MFC) using the microorganism Acetobacter aceti as the biocatalyst in the anode compartment with glucose as a fuel. The periplasmic membrane bound pyrroloquinoline quinone (PQQ) containing enzymes of these genera provide fast and highly efficient oxidation of a wide variety of substrates and helps in the direct routing of electrons to the anode. We describe our preliminary findings with regard to the use of electrochemically deposited manganese oxide films on carbon substrates as cathode materials in MFCs. Manganese oxide was electrochemically deposited on carbon paper in the presence and in the absence of the surfactant, sodium lauryl sulfate (SLS). Electrochemical characterizations of the electrodeposited films are carried out by cyclic voltammetry and impedance spectroscopy. Structural characterization of the film is carried out by XRD, XPS, and SEM. The XPS studies reveal that the presence of Mn4+ (as MnO2) in the absence of SLS and Mn3+/2+ (as Mn3O4or Mn2O3 or MnOOH) ion in the presence of SLS. The power output obtained from MnO2 cathode was 666 ± 9 mW m−3 and it is the highest value reported for MFCs with cubical configuration with the same cathode.