Zinc-based metal organic framework on carbon fiber brush as a novel anode of yeast-based microbial fuel cell

A microbial fuel cell (MFC) is an eco-friendly device that uses living microorganisms' catalytic activity for energy harvesting. The power output of this device is still far from the targeted one. An improvement to the power can be accessed via the use of biocompatible high surface area anode materials. Metal-organic frameworks (MOFs) have a high surface area, crystalline, and can be prepared in different morphologies. MOF demonstrated excellent performance in various energy conversion/storage devices. For the first time, a standalone carbon fiber brush electrode modified with Zn-MOF is constructed via a simple hydrothermal approach. The prepared electrodes were investigated as the anode of yeast-based MFC. The MFC with Zn-MOF carbon fiber brush exhibited maximum current and power densities of 317 mA/m2 and 73.7 mW/m2, which are twofold those obtained using bare carbon brush anodes. The significant improvement in the MFC performance with modified carbon fiber brush would be related to the role of the Zn-MOF in facilitating the electron transfer between the anode and the yeast cells and thus promoting bio electro-catalytic activity as confirmed from the redox peaks that appeared during the cyclic voltammetry (CV) of the modified electrodes and supported by electrochemical impedance spectroscopy (EIS).(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.