Application Of Microbial Fuel Cells Research Articles

A novel MXene coated liquid crystal display anode derived from a futile computer monitor for microbial fuel cell application

A Ti3C2Tx MXene nanosheet-coated liquid crystal display (LCD) anode is meticulously crafted through precision waterjet cutting, salvaging a discarded LCD monitor. This technique, preserving structural integrity and enhanced electrical conductivity, sets it apart from conventional methods. The resulting MXene-coated LCD anode is well-suited for microbial fuel cell (MFC) applications. Comparative assessments against costlier carbonaceous electrodes like graphite felt and carbon cloth, emphasize that the water-jet cut LCD anode with Ti3C2Tx MXene coating is 3.79 and 2.51 times more cost-effective, with an approximate total cost of $38/m2. Substituting Ti3C2Tx MXene-coated LCD for carbon cloth and graphite felt anodes reduces MFC unit fabrication costs by 19 and 10.45 %, respectively. Notably, the Ti3C2Tx MXene LCD anode-based MFC unit boasts a power density per unit cost of 0.008 W/m2/$, underscoring economic viability. This research highlights waterjet cutting's pivotal role in crafting Ti3C2Tx MXene LCD anodes, opening avenues for scalable, cost-effective electrode production in renewable energy applications.

Three-dimensional biochar aerogel anode derived from expired yogurt for enhancing power efficiency and electron transfer at the bacteria-anode interface in microbial fuel cells

Microbial fuel cells (MFCs) are a promising and sustainable form of fuel cells that utilize electroactive microorganisms to generate electricity. However, the practical application of MFCs is limited by their low power density, inadequate biocompatibility, and suboptimal electrochemical properties. To overcome these challenges, we developed a three-dimensional high performance biochar aerogel anode (YP) made from a mixture of expired yogurt and polyvinyl alcohol (PVA) and investigated its effect on the performance of the MFC. The incorporation of PVA into the YP anodes resulted in improved electrolyte wettability and hydrophilic surfaces, thereby enhancing biocompatibility and bacterial adhesion, especially with Geobacter, reaching up to 89.6% coverage. The biofilm content reached 68.1 mg, which is 1.7 times that of carbon cloth, which improved the electron transfer efficiency at the bacteria-anode interface. Moreover, the mechanical strength of the YP anodes was increased, improving anode stability and durability. In addition, the aerogel anode exhibited impressive power density and current density values of 15.87 W m−3 and 43.76 A m−3, respectively. These values are 3.16 times and 3.60 times higher than the 5.03 W m−3 and 12.13 A m−3 of carbon cloth. This study makes a significant contribution to improving power generation in MFCs, optimizing electron transfer at the bacteria-anode interface, and paving the way for future practical applications of MFCs.

Synergistic reduction of pollution and carbon mitigation in constructed wetlands-microbial fuel cell using sludge-derived biochar

Integrating microbial fuel cells (MFC) into constructed wetland systems (CW) has been an efficient wastewater treatment to improve the pollutants removal and regenerate power energy. This study fabricated a sludge biochar material (SBM) to sequestrate the carbon of residual sludge. Thereafter used SBM and modified SBM as the substrate materials to construct three groups of CW-MFC for decreasing the greenhouse gas (GHG) emission. The water quality improvement in removal efficiency achieved (2.59 %, 3.10 %, 5.21 % for COD; 3.31 %, 3.60 %, 6.71 % for TN; 1.80 %, 7.38 %, 4.93 % for TP) by the application of MFC, SBM, and modified SBM in wastewater treatment, respectively. Additionally, the reduction in global warming potential (GWP) realized 17.2 %, 42.2 %, and 64.4 % resulting from these applications. The carbon flow and fate diagrams showed MFC shifted the gas phase‑carbon flow from CH4 to CO2, and SBM promoted this shift trends. Microbial diversity indicated enrichment of electrochemically active bacteria (EAB), denitrifying bacteria, and phosphate accumulating organisms (PAOs) by SBM. Metabolic pathways analysis showed that introduction of MFC and SBM exhibited significant increases of key functional genes in metabolic pathway of anaerobic oxidation of methane (AOM). This study highlights the benefit of CW-MFC in and provides a new strategy for removing pollutants and abating GHG emissions in wastewater treatment.

An innovative fast-start aerobic anode microbial fuel cell biosensor for copper ion detection

The potential of microbial fuel cells (MFCs) based biosensors for water monitoring and early warning is widely recognized. However, the electrochemically active biofilms (EABs) are typically obtained under anaerobic conditions and the formation requires a lengthy time span, which critically limits the application and advancement of the MFCs based monitoring technology. To accelerate the formation rate of EABs and thus shorten the establishment time of MFCs to better meet the needs for early warning and detection of pollutants in the actual aerobic water environment, the aerobic sludge was employed as an inoculation source to construct the MFCs sensing system in this study. It was revealed that biofilms with stable electrochemical properties could be promptly formed within 35 h, reaching a level far ahead of previous studies. Moreover, toxicity tests for copper (Cu2+) ions at concentrations of 1 mg/L, 10 mg/L, and 50 mg/L demonstrated outstanding performance with the maximum inhibition rates of 19.99%, 46.65%, and 53.02% respectively. Remarkably, the response time was found to decrease significantly with the increase of copper ion concentrations. Our results thus open up a new avenue for achieving rapid start-up of MFCs in aerobic conditions, which facilitates the applicability of MFCs based biosensing technology.

Electricity generation and real oily wastewater treatment by Pseudomonas citronellolis 620C in a microbial fuel cell: pyocyanin production as electron shuttle

In the present study, the potential of Pseudomonas citronellolis 620C strain was evaluated, for the first time, to generate electricity in a standard, double chamber microbial fuel cell (MFC), with oily wastewater (OW) being the fuel at 43.625 mg/L initial chemical oxygen demand (COD). Both electrochemical and physicochemical results suggested that this P. citronellolis strain utilized efficiently the OW substrate and generated electricity in the MFC setup reaching 0.05 mW/m2 maximum power. COD removal was remarkable reaching 83.6 ± 0.1%, while qualitative and quantitative gas chromatography/mass spectrometry (GC/MS) analysis of the OW total petroleum and polycyclic aromatic hydrocarbons, and fatty acids revealed high degradation capacity. It was also determined that P. citronellolis 620C produced pyocyanin as electron shuttle in the anodic MFC chamber. To the authors’ best knowledge, this is the first study showing (phenazine-based) pyocyanin production from a species other than P. aeruginosa and, also, the first time that P. citronellolis 620C has been shown to produce electricity in a MFC. The production of pyocyanin, in combination with the formation of biofilm in the MFC anode, as observed with scanning electron microscopy (SEM) analysis, makes this P. citronellolis strain an attractive and promising candidate for wider MFC applications.

Performance of Dual Chamber Microbial Fuel Cells with Waste Water for Power Production and Treatment

Abstract: Dual-chamber microbial fuel cells (MFCs) have garnered significant attention in recent years due to their promising potential for sustainable energy generation from organic waste. This review provides a comprehensive overview of the advancements, challenges, and future prospects of dual-chamber MFC technology. The paper begins with an introduction to the principles of microbial fuel cells and the rationale behind the dual-chamber configuration. It discusses the design considerations including electrode materials, membrane selection, and reactor configurations, highlighting recent innovations aimed at enhancing performance and scalability. Key advancements in dual-chamber MFCs are reviewed, focusing on improvements in power output, microbial community dynamics, and substrate utilization. Strategies such as microbial enrichment, biofilm engineering, and electrode modifications are discussed in detail, showcasing their impact on MFC performance and stability. Furthermore, the review explores the application of dual-chamber MFCs in various fields including wastewater treatment, bioenergy productions.

Nano-Fe3O4/polymerize aniline/carbon cathode based microbial fuel cell for efficient power generation and uranium separation

Microbial fuel cells (MFCs) have gained increasing attention in the field of uranium-containing wastewater (UCW) treatment as a self-powered bioelectrochemical system (BES) due to its advantages of recovering uranium resources and generating electricity. However, the lack of catalytic active sites on the carbon fiber cathode significantly hinders the reaction performance of surface electrons with uranium ions in solution, thereby limiting the application of MFC. In this study, we propose a carbon brush (CB) cathode modification process that utilizes cyclic voltammetry synthesis technique (CVS) to polymerize aniline (PA) on the surface of carbon fibers and uniformly load nano-Fe3O4 particles (nFe3O4). The loading of PA/nFe3O4 not only significantly improve the catalytic active sites but also enhance the synergistic effect of adsorption and conductivity of CB cathode. Consequently, the nFe3O4/PA/CB-MFC showed excellent ability to continuous power generation and uranium separation. Over eight cycles of uranium separation, the nFe3O4/PA/CB-MFC exhibited an average maximum power density of 15.17 mW/m2 and a uranium separation efficiency of 95.52 %, showcasing substantial enhancements by 2.10-fold and 1.44-fold compared to the CB-MFC, respectively. Our study presents an efficient approach to enhance the efficiency of uranium separation and boost power density of MFC by increase catalytic active sites on carbon-based cathode.

Next‐Generation Proton‐Exchange Membranes in Microbial Fuel Cells: Overcoming Nafion's Limitations

The adoption of microbial fuel cell (MFC) technology hinges on the development of efficient proton‐exchange membranes (PEMs), which significantly influences fuel cell performance and cost. PEMs have a critical role in preventing oxygen crossover, maintaining electrochemical neutrality, and supporting microorganisms within MFCs. Nafion, the current industry‐standard PEM, grapples with environmental, cost, and performance issues. Although improvements to Nafion have been reported using additives, immersion in heteropolyacids, different pretreatment methods, and UV irradiation, many of the challenges still remain. Herein, the recent developments in the area of alternative PEMs are reviewed and analyzed. Among them, sulfonated aromatic hydrocarbons, particularly sulfonated polyether ether ketone, have emerged as top contenders in terms of scale up and commercial viability. At the same time, membranes based on polyvinyl alcohol, ionic liquids, and natural materials are also being actively researched for various MFC applications. Since most studies are short term and lab scale, there is a need evaluate long‐term stability and economic cost of PEMs in terms of standardized parameters such as power‐to‐cost and normalized energy recovery. Additionally, for emerging low‐energy‐density MFC applications like biosensors and in vivo power sources, PEM properties and design need to be tailored carefully.

Environmental impacts estimation by life cycle assessment of bioanodes fabricated from devilfish bone chars and their application in microbial fuel cells to produce bioenergy

ABSTRACT This study estimated the environmental impacts by life cycle assessment (LCA) of bioanodes fabricated from devilfish bone chars and their application in microbial fuel cells (MFC). Two types of devilfish bone chars were obtained by calcination using nitrogen (BCN) and air (BCA) as purge gases. Two bioanodes were fabricated with BCN and BCA and applied independently in MFC to produce bioenergy from ibuprofen and carbamazepine biodegradation. LCA was performed using the methodology ISO 14,040. 1 kg of fabricated bioanode and 1 kWh of produced bioenergy were the established functional units, integrating a detailed inventory of the materials’ fabrication and application in MFC. The impact assessment was made with SimaPro 9.2 software and the ReCiPe 2016 Midpoint (I) method, considering 18 impact categories. Results showed that the bioanode fabricated with BCN has less environmental impacts (1.09 times) than BCA, finding the highest impact in the categories of human carcinogenic toxicity (1.04 kg 1,4-DCB) and human non-carcinogenic toxicity (13.60 kg 1,4-DCB). The environmental impacts in MFC-Ibuprofen were 3.1 times higher than MFC-Carbamazepine in the same impact categories, with 12.76 kg 1,4-DCB and 168.34 kg 1,4-DCB, respectively. Therefore, it is recommended to use BCN to fabricate the bioanode and to apply it in MFC to produce bioenergy from carbamazepine biodegradation. Although the LCA was performed with data obtained at a laboratory level, the results provide information on the environmental impacts that could be generated if both processes are transferred on a large scale, identifying opportunities for improvement to reduce these impacts.

Valorising lignocellulosic biomass to high-performance electrocatalysts via anaerobic digestion pretreatment

AbstractAnaerobic digestion (AD) was initially evaluated as a potential preprocessing method for preparing biomass-based carbon electrocatalysts in this study. The AD pretreatment succeeded in the structural depolymerization and nitrogen enrichment of Hybrid Pennisetum, which provided favorable conditions to achieve efficient and homogeneous nitrogen introduction due to microorganism community enrichment and provided a porous structure by degradation of the biodegradable components. The resulted biochar exhibited improved physiochemical properties including higher specific surface areas, nitrogen content and graphitization degree than that obtained from pyrolyzing raw biomass. These improvements were positively correlated with the AD time and showed to have enhanced the performance in oxygen reduction reaction and practical microbial fuel cell applications. Amongst the investigated samples, the obtained biochar pretreated by AD for 15 days exhibited the most excellent performance with an onset potential of 0.17 V (VS. saturated calomel electrode) and the maximal power density of 543.2 mW cm−2 assembled in microbial fuel cells. This study suggested applying AD as a new biological pretreatment in the preparation of biomass-based electrocatalysts, and provided a unique pathway for fabricating high-performance biochar-based catalysts by structure optimization and N-containing active sites construction via gentle biological method, thereby providing a cost-effective method to fabricate metal-free catalysts for oxygen reduction reaction. Graphical Abstract

Enhanced performance of acridine degradation and power generation by microbial fuel cell with g-C3N4/PANI-DA/CF anode

Microbial fuel cell (MFC) has attracted much attention in treating organic wastewater due to its double functions of degrading organics and generating electricity with microorganisms as biocatalysts. Unfortunately, some organics with biological toxicity such as acridine could inhibit the growth and activity of the microorganisms on the anode so that the double functions of MFC would recede. Enhancing microbial activity by using new biocompatible materials as anodes is prospective to solve problem. A novel anode was achieved by electrodepositing g-C3N4 sheets to the carbon felt (CF) modified with polyaniline-dopamine composite film, and used to treat wastewater containing acridine for the first time. After the operation of 13 d, MFC loading with the composite anode showed a degradation efficiency of 98.3% in 150 mg L−1 acridine, while that of CF-MFC was 55.8%. Moreover, MFC loading the modified anode obtained a maximum power density of 1976 ± 47 mW m−2, 140.1% higher than that of CF-MFC. Further analysis revealed that the functional microorganisms associated with acridine degradation such as Achromobacter and Alcaligenes were enriched on the g-C3N4/PANI-DA/CF anode. Moreover, the composite anode could improve the activity of microorganisms and elicit them to generate conductive nanowires, which was beneficial to transferring electrons from microbes to anode over long distances, suggesting a promising prospect application in MFC.

The influence of various chemical oxygen demands on microbial fuel cells performance using leachate as a substrate.

Microbial fuel cells (MFCs), hailed as a promising technology, hold the potential to combat various wastewater pollutants while simultaneously converting their chemical energy into electricity through biocatalysts. This study explores the applicability of a dual compartment MFC (DC-MFC) under varying conditions, targeting the removal of chemical oxygen demand (COD) from landfill leachate and electricity generation. In this setup, anaerobic sludge from a wastewater treatment plant serves as the inoculum in the anode compartment of the MFC, with a Nafion117 membrane acting as the separator between MFC units. The cathode compartments are filled with distilled water and continually aerated for 24 h to enhance air supply. The study assesses the MFC's performance across different COD concentrations, focusing on COD removal, power generation, and Coulombic efficiency. The findings reveal that COD removal efficiency is notably enhanced at higher concentrations of organic matter. Specifically, at a COD concentration of 3325.0 mg L-1, the MFC exhibited the highest COD removal efficiency (89%) and maximum power density (339.41 mWm-2), accompanied by a Coulombic efficiency of 25.5%. However, as the initial substrate concentration increased to 3825 mg L-1, the efficiency decreased to 72%, with a Coulombic efficiency of 13.56% and a power density of 262.34 mWm-2. Optical density levels increased due to bacterial growth at ambient temperature and neutral pH, reflecting the dynamic microbial response within the system.

Bioelectrocatalytic reduction by integrating pyrite assisted manganese cobalt-doped carbon nanofiber anode and bacteria for sustainable antimony catalytic removal

A novel manganese cobalt metal–organic framework based carbon nanofiber electrode (MnCo/CNF) was prepared and used as microbial fuel cell (MFC) anode. Pyrite was introduced into the anode chamber (MnCoPy_MFC). Synergistic function between pyrite and MnCo/CNF facilitated the pollutants removal and energy generation in MnCoPy_MFC. MnCoPy_MFC showed the highest chemical oxygen demand removal efficiency (82 ± 1%) and the highest coulombic efficiency (35 ± 1%). MnCoPy_MFC achieved both efficient electricity generation (maximum voltage: 658 mV; maximum power density: 3.2 W/m3) and total antimony (Sb) removal efficiency (99%). The application of MnCo/CNF significantly enhanced the biocatalytic efficiency of MnCoPy_MFC, attributed to its large surface area and abundant porous structure that provided ample attachment sites for electroactive microorganisms. This study revealed the synergistic interaction between pyrite and MnCo/CNF anode, which provided a new strategy for the application of composite anode MFC in heavy metal removal and energy recovery.

An overview of agro-industrial wastewater treatment using microbial fuel cells: Recent advancements

Discharge of agro-industrial wastewater causes severe damage to the environment due to the various hazardous components it contains. Progressive circular agriculture and industry involve closed cycles and zero-waste principles; therefore, waste treatment for subsequent reuse is of great interest. The microbial fuel cell (MFC) is a promising sustainable technology capable of treating wastewater at low cost without greenhouse gas (GHG) emissions while simultaneously producing electricity. The principle behind MFCs is based on the conversion of chemical energy into electricity using electrochemically active bacteria (EAB) as a biocatalyst. This article presents an overview of the progress and recent advancements in MFCs as a pivotal technology for agro-industrial wastewater treatment with production of sustainable electricity, compared to conventional treatment processes. Furthermore, the fundamental aspects of the design, configuration, operation, and application of MFCs in wastewater treatment (i.e., removal of inorganic nutrients, nitrate, phosphate, sulfate, sulfide, ammonium, organics, dyes, carbohydrates, fatty acids, and petroleum) are comprehensively discussed. Despite the viability and potential of MFCs in treating agro-industrial wastewater and producing electricity, they face various limitations and significant challenges, which are highlighted in this review. Future opportunities and perspectives on MFC applications are also discussed. Further research is required to address MFC limitations, which could make them feasible and practicable for real-world applications. However, MFC technology is clearly an excellent option for simultaneous wastewater treatment and electricity production without the need for external energy sources.

Non-precious HfO2 nanoparticle as an alternative cathode catalyst for microbial fuel cell applications

This study evaluated hafnium oxide (HfO2) as a cathode catalyst material in air-cathode single-chamber microbial fuel cells (SCMFCs). Various HfO2 crystalline phases, synthesized via a precipitation method under specific temperature conditions, were examined for electrochemical performance in MFCs, including voltage, power generation, cyclic voltammetry, and impedance spectroscopy. The MFC-600 °C variant outperformance MFC-500 °C and MFC-700 °C yielding power density of 1152 ± 9 mW m−2 and voltage 284 ± 8 mV. In a double loading (DL) configuration (1 mg cm−2), MFC-600 °C exhibited higher power density than single loading and triple loading. The MFC-600 °C DL electrode showed up to 57.3% of the performance of the traditional Pt/C cathode (2009 ± 12 mW m−2). On the other hand, when considering catalyst loading, the 10% Pt/C (0.5 mg cm−1) had a lower power density than the HfO2 600 °C DL (1 mg cm−1): 4.018 mW m−2 g−1 vs. 11.52 mW m−2 g−1. These findings highlight the promising viability of the HfO2 cathode as an economically advantageous catalyst material for MFCs, potentially paving the way for commercialization.

Exogenous electric field as a biochemical driving factor for extracellular electron transfer: Increasing power output of microbial fuel cell

Although microbial fuel cells (MFCs) offer a promising avenue for clean power production, they are hindered by inefficient extracellular electron transfer (EET), thereby resulting in a low power output. This study focused on augmenting MFC power by boosting the EET rate using an exogenous electric field (EEF). By leveraging the dual benefits of microbial electrolysis cells (MECs) in organic waste treatment and energy recovery, we developed an MFC–MEC system that utilizes the EEF from MEC as a connecting link. Two configurations, EEF in the same direction (SD-MFC–MEC) and EEF in the reverse direction (RD-MFC–MEC), were used to examine the EET kinetic rate at the MFC anode in the EEF environment using various electrochemical methods for quantitative evaluation. Our findings revealed that EEF significantly enhanced MFC anode biofilm formation and electrochemical activity, leading to a prominent improvement in electrode reaction rates. The EET rate constants in the SD-MFC–MEC and RD-MFC–MEC were more than double those in the control R-MFC, with power density increases of 117.8% and 108.4%, respectively. The formation of electrochemically active sites within the biofilm induced by EEF has emerged as a crucial factor in amplifying the EET rate, and consequently, the MFC power output. Additionally, the variation in EET rate constants between the SD-MFC–MEC and RD-MFC–MEC was minimal, thereby indicating the negligible impact of the EEF orientation on the EET efficiency. This study provides a novel method for quantitatively examining EET rates, opens up new avenues for further facilitating microbe-to-electrode electron transfer, and promotes the application of MFC–MEC systems in energy recovery, CO2 emission reduction, and waste treatment.

Highly conductive riboflavin-based carbon quantum dot–embedded SiO2@MoS2 nanocomposite for enhancing bioelectricity generation through synergistic direct and indirect electron transport

A microbial fuel cell (MFC) is an advanced green battery that has limited application because of its low current density. In the present study, Shewanella oneidensis MR-1, which is an electricity-producing bacterium, was used in an electrochemical reactor as a bacterial model. Mesoporous spherical silica nanoparticles (NPs) loaded with riboflavin (RF) were prepared as the starting material, following which surface modification was conducted to expose the thiol group, which considerably increased the affinity of the NPs to MoS2 and resulted in the formation of a dense MoS2 shell on the surface after calcination. Moreover, the loaded RFs were successfully transformed into RF-based carbon quantum dots (CQDs), which resulted in a substantial increase in conductivity. The CQD-embedded SiO2@MoS2 NPs, which contained redox-active N-doped CQDs and had a metallic MoS2 shell, were able to receive electrons from exoelectrogenic bacteria (charging) and transfer electrons to an indium tin oxide electrode (discharging). Thus, these NPs could act as an electron nanoshuttle and a conductive medium in biofilms for enhancing systematic extracellular electron transport. A 10-fold increase in bioelectricity production than no NPs addition was achieved, which confirmed the applicability of the aforementioned NPs in advanced MFC applications. The NPs prepared in this study, which mimic biological electron shuttles (e.g., RF) in long-distance conduction, can usher in a new era in the development of advanced MFCs.

Graphitized mango seed as an effective 3D anode in batch and continuous mode microbial fuel cells for sustainable wastewater treatment and power generation.

Herein, we explored the utilization of graphitized mango seeds as 3D-packed anodes in microbial fuel cells (MFCs) powered by sewage wastewater. Mango seeds were graphitized at different temperatures (800 °C, 900 °C, 1000 °C, and 1100 °C) and their effectiveness as anodes was evaluated. Surface morphology analysis indicated that the proposed anode was characterized by layered branches and micro-sized deep holes, facilitating enhanced biofilm formation and microorganism attachment. Maximum power densities achieved in the MFCs utilizing the mango seed-packed anodes graphitized at 1100 °C and 1000 °C were 2170.8 ± 90 and 1350.6 ± 125 mW m-2, respectively. Furthermore, the weight of the graphitized seed anode demonstrated a positive correlation with the generated power density and cell potential. Specifically, MFCs fabricated with 9 g and 6 g anodes achieved maximum power densities of 2170.8 ± 90 and 1800.5 ± 40 mW m-2, respectively. A continuous mode air cathode MFC employing the proposed graphitized mango anode prepared at 1100 °C and operated at a flow rate of 2 L h-1 generated a stable current density of approximately 12 A m-2 after 15 hours of operation, maintaining its stability for 75 hours. Furthermore, a chemical oxygen demand (COD) removal efficiency of 85% was achieved in an assembled continuous mode MFC. Considering that the proposed MFC was driven by sewage wastewater without the addition of external microorganisms, atmospheric oxygen was used as the electron acceptor through an air cathode mode, agricultural biomass waste was employed for the preparation of the anode, and a higher power density was achieved (2170.8 mW m-2) compared to reported values; it is evident that the proposed graphitized mango seed anode exhibits high efficiency for application in MFCs.

Nanofiber applications in microbial fuel cells for enhanced energy generation: a mini review.

Microbial fuel cells (MFCs) represent simple devices that harness the metabolic activities of microorganisms to produce electrical energy from diverse sources such as organic waste and sustainable biomass. Because of their unique advantage to generate sustainable energy, through the employment of biodegradable and repurposed waste materials, the development of MFCs has garnered considerable interest. Critical elements are typically the electrodes and separator. This mini-review article presents a critical assessment of nanofiber technology used as electrodes and separators in MFCs to enhance energy generation. In particular, the review highlights the application of nanofiber webs in each part of MFCs including anodes, cathodes, and membranes and their influence on energy generation. The role of nanofiber technology in this regard is then analysed in detail, focusing on improved electron transfer rate, enhanced biofilm formation, and enhanced durability and stability. In addition, the challenges and opportunities associated with integrating nanofibers into MFCs are discussed, along with suggestions for future research in this field. Significant developments in MFCs over the past decade have led to a several-fold increase in achievable power density, yet further improvements in performance and the exploration of cost-effective materials remain promising areas for further advancement. This review demonstrates the great promise of nanofiber-based electrodes and separators in future applications of MFCs.

Cobalt-Intercalated Birnessite-Type Manganese Oxide Catalysts for Low-Cost Cathodes in Microbial Fuel Cells

Microbial fuel cells (MFCs) are a promising technology for solving energy and water pollution problems. However, to promote the practical application of MFC, it is necessary to solve the problems of power output and electrode cost simultaneously. Therefore, transition metal-based catalysts that can improve air cathode functionality without using platinum catalysts, which are commonly used, are attracting attention. In this experiment, a cobalt-intercalated birnessite-type manganese oxide catalyst was used as the cathode of the MFC. In addition, rice husk charcoal from agricultural waste and Sumi ink were used as cathode materials to reduce cost and improve the physical stability of the electrodes. The conductivity of the Sumi ink is expected to compensate for the low conductivity of manganese oxide. The resulting power density was 5.8 times higher with the catalyst than without. It was also confirmed that the fabricated cathode operated for at least 90 days without maintenance.