Polyaniline Incorporated MOF Modified Anode in Microbial Fuel Cell for Enhanced Bioelectricity Generation

Abstract

Microbial fuel cells (MFC) are acknowledged as a highly promising device for generating environmentally friendly and sustainable electricity. The anode plays a crucial role in the electricity generation process in MFC. The microorganisms in the anodic chamber undergo oxidation of organic substrates, resulting in the release of electrons and protons. Subsequently, these electrons are transferred to the surface of the anode, resulting in the generation of an electric current. When protons originating from the anode traverse a proton exchange membrane (PEM) and electrons flowing through an external circuit react with oxygen to produce water at the cathode, the electrochemical circuit is finalized. Utilizing polyaniline/Fe-MIL-88B-NH2 (PANI/Fe-MOF) as an anode material shows great potential in enhancing MFC performance. Fe-MOF is a material that possesses a substantial surface area and can have its chemical properties tuned. The objective is to optimize the catalytic properties of Fe-MOF to enhance the performance of MFCs. This will be achieved by depositing Fe-MOF onto the surface of the anode, thereby accelerating electron transfer. PANI can enhance the redox activity, stability, and conductivity of the electrode surface. The Fe-MOF is synthesized using a room temperature synthesis approach, and then the PANI is polymerized in-situ to form a composite of PANI/Fe-MOF. The MFC operated using the PANI/FeMOF@Graphite Felt (GF) anode, exhibited the highest power density of 277 mW/m2 and a maximum output of 319 mV at an external resistance of 1000 Ω. This surpassed the power density and output voltage of both the Fe-MOF@GF (154 mW/m2 , 202 mV) and the unmodified GF (45 mW/m2 , 161 mV). The enhanced performance can be ascribed to the material's reduced charge transfer resistance (Rct) in conjunction with its boosted affinity for bacteria, leading to an augmented efficiency in extracellular electron transfer (EET). This study demonstrates that the PANI/Fe-MOF composite exhibits promising potential as an anode for power generation in MFCs