Microbial Fuel Cells: Nanomaterials Based on Anode and Their Application

Abstract

Microbial fuel cells (MFCs) exhibit great potential to generate power through organic wastewater treatment. Limitations have restricted the advanced development of MFCs, including low power density, expensive electrode materials, and the challenge to manufacture MFCs in large scale. However, the introduction of advanced anode materials, especially porous and nanostructured materials, is believed to be an effective way to solve the problems, as they can promote bacteria extracellular electron transfer (EET) because of their unique physical, chemical, and electrical properties. Nanostructured materials, including carbon nanotubes (CNTs), graphene, activated carbon fiber, metal, metal oxides and conductive polymers, show many appreciable properties such as good conductivity, large specific surface area, and excellent catalytic activity. Additionally, nanomaterials with unique electrochemical properties provide strong charge interactions with organic compounds and the direct electrochemistry process between bacteria and the anode. This Review comprehensively focuses on the recent development of modification of nanostructured anode materials in view of crucial intrinsic factors to enhance electricity output. Furthermore, the enhanced performance of MFCs and the corresponding known mechanism is also discussed, which enables active bacteria to facilitate electron transfer. Finally, promising strategies to modify anode nanomaterials for future research are presented.

Microbial Electrochemical Systems: Principles, Construction and Biosensing Applications

“…Nanostructured materials, such as metal and metal oxide nanoparticles (NPs), or nano-hybrids have been employed in the construction of MESs [ 138 ]. Carbon nanostructures have shown promising performance as electrode material, due to their high electrical conductivity, biocompatibility, and electrocatalytic properties [ 139 ].…”

“…Owing to their unique characteristics such as high surface-to-volume ratio, electrocatalytic activity, electrical and mechanical properties, nanomaterials have intensively studied for use in MESs particularly for accelerating the electron transfer [ 11 , 155 , 156 ] and promote microbial-electrode adherence and biofilm formation [ 138 , 157 ].…”

From Microorganism-Based Amperometric Biosensors towards Microbial Fuel Cells

“…Nanoparticles act as the bridge for electron transfer between bacteria and anode. In contrary to carbon nanomaterials, metal nanoparticles are not very widely applied because of their corrosiveness [ 53 ] and cytotoxicity [ 54 ]. However, gold nanoparticles (AuNPs) and their composites are considered as suitable for electrode modification in bioelectrochemical devices due to their wide array of beneficial properties, such as biocompatibility, high surface-to-volume ratio, and enhanced conductivity [ 55 ].…”

Carbon material‐based anodes in the microbial fuel cells

“…Besides, the surface properties can be regulated to increase the anode/bacteria interactions, thus enhancing the EET and the formation of biofilm. [39][40][41][42] Most of the commercial carbon electrodes belong to planar electrodes, where the biofilm formation and electron transfer are confined to the outer surface. To accelerate the diffusion of self-secreted mediators and even the formation of natural biofilm on the interior space of anode, the freestanding carbon materials with tailored porous structures are also developed as candidates for commercial carbon electrodes.…”

“…The modification of these carbon‐based nanomaterials can enlarge the surface area of commercial carbon electrodes, leading to the increased spatial positions for bacterial attachment and biofilm formation. Besides, the surface properties can be regulated to increase the anode/bacteria interactions, thus enhancing the EET and the formation of biofilm 39–42 . Most of the commercial carbon electrodes belong to planar electrodes, where the biofilm formation and electron transfer are confined to the outer surface.…”