Graphitic biochar as a cathode electrocatalyst support for microbial fuel cells
By Tyler M. Huggins and Jeremy J. Pietron and Heming Wang and Zhiyong Jason Ren and Justin C. Biffinger
Published in Bioresource Technology
2015
Abstract
Graphitic biochar (BC) was generated using high temperature gasification and alkaline post-treatment (BCw) of wood-based biomass. The \BCw\ was evaluated as a manganese oxide electrocatalytic support (MnO/BCw) and microbial fuel cell (MFC) air cathode. Nano-structured MnO2 crystals were successfully immobilized on biomass-based graphitic sheets and characterized using physical, chemical, and electrochemical analyses. Cyclic voltammetry of MnO/BCw/Nafion inks showed electrochemical features typical of ?-MnO2 with a current density of 0.9 mA cm?2. \BC\ showed satisfactory maximum power densities of 146.7 mW m?2 (BCw) and 187.8 W m?2 (MnO/BCw), compared with Vulcan Carbon (VC) (156.8 mW m?2) and manganese oxide \VC\ composites (MnO/VC) (606.1 mW m?2). These materials were also tested as oxygen reduction reaction (ORR) catalysts for single chamber \MFCs\ inoculated with anaerobic sludge. Our results demonstrate that \BC\ can serve as an effective, low cost, and scalable material for \MFC\ application.