Pengbo Zhang, Xin Zhou, Ruilian Qi et al.

Advanced Electronic Materials • 2019

Low organism loading capacity and inefficient extracellular electron transport (EET) are still the bottlenecks hindering the development of bioelectrochemical systems (BESs). It is shown that cationic polythiophene derivative (PMNT) has the ability to simultaneously enhance bacteria biofilm formation, improve the bacteria viability, decrease the resistance value, and accelerate the EET process between exoelectrogen and the electrode. Shewanella oneidensis can form a robust and thick biofilm on the electrode surface in the presence of PMNT. Mediated by electron‐transporting PMNT, even bacteria far away from the electrode can transfer electrons to it. This bioelectrode is utilized as the anode to construct a microbial fuel cell, which exhibits a greatly increased maximum current density and power density and a prolonged lifetime by taking advantage of the unique properties of PMNT. Thus, cationic conductive polymers exhibit great potential as effective biofilm enhancers and electron transporters in BESs.

Alec Agee, Ariel L. Furst

ECS Meeting Abstracts • 2023

Microbial electrocatalysis is an emerging technology which enables electricity generation directly from organic feedstocks, many of which are otherwise difficult to harness for renewable energy. While microbes possess unique advantages for these applications, their use in practical settings is currently limited by inefficient electron transfer from cells to electrodes. To address this bottleneck, we have developed improved electrode materials that combine principles of conductive polymer design with lessons from enzymatic electron transfer reactions. Our polymer electrodes exhibit superior nanoscale electroactive area and enable concerted two-electron transfer from the electron carrier flavin mononucleotide (FMN) to an abiotic surface, a high efficiency mechanism which was previously restricted to biological contexts. Electroactive microbes exhibited greatly improved current production on polymer electrodes in quantitative agreement with in vitro electrochemical properties. Our findings establish bio-inspired functionalization as a useful paradigm to bridge the gap between microbial metabolism and abiotic electrochemistry.

Matteo Grattieri, Nelson D Shivel, Iram Sifat et al.

ChemSusChem • 2017

Microbial fuel cells are an emerging technology for wastewater treatment, but to be commercially viable and sustainable, the electrode materials must be inexpensive, recyclable, and reliable. In this study, recyclable polymeric supports were explored for the development of anode electrodes to be applied in single-chamber microbial fuel cells operated in field under hypersaline conditions. The support was covered with a carbon nanotube (CNT) based conductive paint, and biofilms were able to colonize the electrodes. The single-chamber microbial fuel cells with Pt-free cathodes delivered a reproducible power output after 15 days of operation to achieve 12±1 mW m-2 at a current density of 69±7 mA m-2 . The decrease of the performance in long-term experiments was mostly related to inorganic precipitates on the cathode electrode and did not affect the performance of the anode, as shown by experiments in which the cathode was replaced and the fuel cell performance was regenerated. The results of these studies show the feasibility of polymeric supports coated with CNT-based paint for microbial fuel cell applications.

Nabin Aryal, Pier-Luc Tremblay, Mengying Xu et al.

Frontiers in Energy Research • 2018

Microbial electrosynthesis (MES) is a bioelectrochemical technology developed for the conversion of carbon dioxide and electric energy into multicarbon chemicals of interest. As with other biotechnologies, achieving high production rate is a prerequisite for scaling up. In this study, we report the development of a novel cathode for MES, which was fabricated by coating carbon cloth with conductive poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) polymer. Sporomusa ovata-driven MES reactors equipped with PEDOT:PSS-carbon cloth cathodes produced 252.5 ± 23.6 mmol d-1 acetate per m2 of electrode over a period of 14 days, which was 9.3 fold higher than the production rate observed with uncoated carbon cloth cathodes. Concomitantly, current density was increased to -3.2 ± 0.8 A m-2, which was 10.7-fold higher than the untreated cathode. The coulombic efficiency with the PEDOT: PSS-carbon cloth cathodes was 78.6 ± 5.6%. Confocal laser scanning microscopy and scanning electron microscopy showed denser bacterial population on the PEDOT:PSS-carbon cloth cathodes. This suggested that PEDOT:PSS is more suitable for colonization by S. ovata during the bioelectrochemical process. The results demonstrated that PEDOT: PSS is a promising cathode material for MES.

G. Puthilibai, J. R, S. T

2020 International Conference on Power, Energy, Control and Transmission Systems (ICPECTS) • 2020

Nowadays there are more efforts taken to improve the techniques associated Microbial Fuel cells and to enhance their potential towards practical application. By incorporating the recent developments in biotechnology and organic chemistry, we can increase the efficiency and performance of MFCs. Due to these incorporations we can achieve low production cost, high portability and easy usage. Bio electrodes and polymeric foam substrate are used in MFCs to enhance the efficiency of MFCs to obtain more energy. The usage of Nanotechnology in the application of conducting material on the electrodes of MFCs has improved its performance. The maximum power density obtained is about 4.20W/m^2.

Chia-Ping Tseng, Fangxin Liu, Xu Zhang et al.

Advanced Materials • 2022

Microbial bioelectronic devices integrate naturally occurring or synthetically engineered electroactive microbes with microelectronics. These devices have a broad range of potential applications, but engineering the biotic–abiotic interface for biocompatibility, adhesion, electron transfer, and maximum surface area remains a challenge. Prior approaches to interface modification lack simple processability, the ability to pattern the materials, and/or a significant enhancement in currents. Here, a novel conductive polymer coating that significantly enhances current densities relative to unmodified electrodes in microbial bioelectronics is reported. The coating is based on a blend of poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) crosslinked with poly(2‐hydroxyethylacrylate) (PHEA) along with a thin polydopamine (PDA) layer for adhesion to an underlying indium tin oxide (ITO) electrode. When used as an interface layer with the current‐producing bacterium Shewanella oneidensis MR‐1, this material produces a 178‐fold increase in the current density compared to unmodified electrodes, a current gain that is higher than previously reported thin‐film 2D coatings and 3D conductive polymer coatings. The chemistry, morphology, and electronic properties of the coatings are characterized and the implementation of these coated electrodes for use in microbial fuel cells, multiplexed bioelectronic devices, and organic electrochemical transistor based microbial sensors are demonstrated. It is envisioned that this simple coating will advance the development of microbial bioelectronic devices.

Sergei E. Tarasov, Yulia V. Plekhanova, Aleksandr G. Bykov et al.

Sensors • 0

<jats:p>A novel conductive composite based on PEDOT:PSS, BSA, and Nafion for effective immobilization of acetic acid bacteria on graphite electrodes as part of biosensors and microbial fuel cells has been proposed. It is shown that individual components in the composite do not have a significant negative effect on the catalytic activity of microorganisms during prolonged contact. The values of heterogeneous electron transport constants in the presence of two types of water-soluble mediators were calculated. The use of the composite as part of a microbial biosensor resulted in an electrode operating for more than 140 days. Additional modification of carbon electrodes with nanomaterial allowed to increase the sensitivity to glucose from 1.48 to 2.81 μA × mM−1 × cm−2 without affecting the affinity of bacterial enzyme complexes to the substrate. Cells in the presented composite, as part of a microbial fuel cell based on electrodes from thermally expanded graphite, retained the ability to generate electricity for more than 120 days using glucose solution as well as vegetable extract solutions as carbon sources. The obtained data expand the understanding of the composition of possible matrices for the immobilization of Gluconobacter bacteria and may be useful in the development of biosensors and biofuel cells.</jats:p>

Md Tabish Noori, Mansi, Shashank Sundriyal et al.

Scientific Reports • 0

<jats:title>Abstract</jats:title><jats:p>Microbial electrosynthesis (MES) presents a versatile approach for efficiently converting carbon dioxide (CO<jats:sub>2</jats:sub>) into valuable products. However, poor electron uptake by the microorganisms from the cathode severely limits the performance of MES. In this study, a graphitic carbon nitride (<jats:italic>g-</jats:italic>C<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub>)-metal–organic framework (MOF) <jats:italic>i.e.</jats:italic> HKUST-1 composite was newly designed and synthesized as the cathode catalyst for MES operations. The physiochemical analysis such as X-ray diffraction, scanning electron microscopy (SEM), and X-ray fluorescence spectroscopy showed the successful synthesis of <jats:italic>g-</jats:italic>C<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub>-HKUST-1, whereas electrochemical assessments revealed its enhanced kinetics for redox reactions. The <jats:italic>g-</jats:italic>C<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub>-HKUST-1 composite displayed excellent biocompatibility to develop electroactive biohybrid catalyst for CO<jats:sub>2</jats:sub> reduction. The MES with <jats:italic>g-</jats:italic>C<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub>-HKUST-1 biohybrid demonstrated an excellent current uptake of 1.7 mA/cm<jats:sup>2</jats:sup>, which was noted higher as compared to the MES using <jats:italic>g-</jats:italic>C<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub> biohybrid (1.1 mA/cm<jats:sup>2</jats:sup>). Both the MESs could convert CO<jats:sub>2</jats:sub> into acetic and isobutyric acid with a significantly higher yield of 0.46 g/L.d and 0.14 g/L.d respectively in MES with <jats:italic>g-</jats:italic>C<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub>-HKUST-1 biohybrid and 0.27 g/L.d and 0.06 g/L.d, respectively in MES with <jats:italic>g-</jats:italic>C<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub> biohybrid. The findings of this study suggest that <jats:italic>g-</jats:italic>C<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub>-HKUST-1 is a highly efficient catalytic material for biocathodes in MESs to significantly enhance the CO<jats:sub>2</jats:sub> conversion.</jats:p>

Tahmineh Taheri Dezfouli, R. Marandi, M. Kashefiolasl et al.

• 2019

The modern BioElectrochemical technologies can convert the energy stored in the chemical bonds of biodegradable organic materials to renewable electrical energy through the catalytic reactions of microorganisms while treating the waste waters. The present research was conducted to evaluate the efficiency of a single-chamber Bioelectrochemical system with the carbon aerogel catalyst, as a simple and inexpensive method, in removing the corrosive and odorous sulfur compounds from municipal wastewater simultaneously with electricity generation by using indigenous bacterial consortium. The used bacteria were isolated from local lagoon sediments, and the municipal wastewater was used as the substrate. During six months of the Bioelectrochemical cell operation, the sulfate concentration was dropped to a minimum of 63 ± 57.2 mg/l, indicating the ability of the system to remove 71.8 % of the sulfate from the municipal wastewater and the production of bioenergy. With a 304 mV Open Circulate voltage, the maximum removal of Chemical Oxygen Demand was 80 % and the maximum power density was 1.82 mW/m2. Carbon aerogel, as a novel material with suitable absorbance and resistance to oxidation at urban wastewater pH, can be, therefore, coated on electrodes to facilitate the Oxidation Reduction Reactions and electricity transmission. The existence of elemental sulfur in the sediments showed that these systems could be optimized to recover the elemental sulfur from the municipal wastewater.

Konstantin G. Nikolaev, Jiqiang Wu, Xuanye Leng et al.

ECS Meeting Abstracts • 2023

There is a high interest in living organism-compatible materials associated with electrically active interfaces. Bacteria/electrode interfaces implement smart, functional systems with responses, based on which it is possible to elaborate self-regulating energy generation systems. Carbon materials have a number of advantages, such as biocompatibility, low electrical resistance, and the possibility of increasing the electrode surface on an industrial scale. The most promising approach for the industrial production of electrodes is 3D printing. We propose a 3D-printed carbon electrode – a novel lightweight material for electrodes in bioelectrochemical systems for efficient bioelectricity utilization. The pyrolytic process for manufacturing carbon electrodes is promising for upscaling and industrial applications. However, there is a problem of volume loss when 3D-printed polymers are pyrolyzed in an inert environment. We propose a new strategy for the thermal treatment of 3D-printed polymers that allow for reduced volume loss under pyrolytic carbonization. In addition, to achieve a higher electrode surface area, the graphene aerogel could be impregnated into the 3D-printed scaffolds. Chemical modification of graphene surface can enhance biocompatibility. Specifically, the oxidation of graphene leads to forming a hydrophilic and biocompatible material. We tune graphene hydrophilic properties and electrical conductivity via control over the thermal reduction of the oxidized form of graphene–graphene oxide1. Such sponge morphology affords 3D-printed carbon scaffolds an excellent lightweight host scaffold for microorganisms, in which the graphene nanowalls are homogeneously occupied by S. oneidensis MR-1. We demonstrate a novel sustainable method to produce graphene-based lightweight 3D printed electrode materials for green energy production from biomass. The proposed technology creates the opportunity for novel, innovative, disruptive graphene applications that can lead to the establishment of new energy-related industries and facilitate many startups in the ecosystem. Acknowledgments This work was supported by the Ministry of Education (Singapore) through the Research Centre of Excellence program (grant EDUN C-33-18-279-V12, I-FIM). References Xuanye Leng, Ricardo J. Vazquez, Samantha R. McCuskey, Glenn Quek, Yude Su, Konstantin G. Nikolaev, Mariana C.F. Costa, Siyu Chen, Musen Chen, Kou Yang, Jinpei Zhao, Mo Lin, Zhaolong Chen, Guillermo C. Bazan, Kostya S. Novoselov, Daria V. Andreeva, Carbon, 205, 2023, 33-39.

Tahmineh Taheri Dezfouli, M. Kashefiolasl, R. Marandi et al.

• 2020

The modern bio-electrochemical technologies can convert the energy stored in the chemical bonds of biodegradable organic materials into renewable electrical bioenergy through the catalytic reactions of the microorganisms while treating the wastewaters. The present research has been conducted to study the efficiency of the single-chamber bio electrochemical system with carbon aerogel catalyst as a new, simple and inexpensive approach to remove and recover the valuable but polluting nutrients (nitrogen and phosphorus) from municipal wastewaters and also determines the optimal conditions to scale up the system in countries with hot, dry climates. In the present study, the bacterial consortium was isolated from the sediments of local lagoons, and the municipal wastewater was used as the substrate. During the six months of cell operation, the effluent of BES showed a 54.9% decrease in nitrate concentration and a 59.8% decrease in total N and 90% of phosphate removed from wastewater, the total nitrogen and total phosphate concentration in effluent were 28.9 ± 24.3 mg/l. and 13 ± 46.8 mg/l, respectively. The maximum removal of COD was 80%, and the maximum power density was 1.82mW/m2. Carbon aerogel as a novel material with suitable absorbance and resistance to oxidation by urban wastewater pH can be coated on electrodes to facilitate the Oxidation Reduction reactions and electricity transmission

Anatoly Reshetilov, Yulia Plekhanova, Sergei Tarasov et al.

Membranes • 0

<jats:p>This work investigated changes in the biochemical parameters of multilayer membrane structures, emerging at their modification with multiwalled carbon nanotubes (MWCNTs). The structures were represented by polyelectrolyte microcapsules (PMCs) containing glucose oxidase (GOx). PMCs were made using sodium polystyrene sulfonate (polyanion) and poly(allylamine hydrochloride) (polycation). Three compositions were considered: with MWCNTs incorporated between polyelectrolyte layers; with MWCNTs inserted into the hollow of the microcapsule; and with MWCNTs incorporated simultaneously into the hollow and between polyelectrolyte layers. The impedance spectra showed modifications using MWCNTs to cause a significant decrease in the PMC active resistance from 2560 to 25 kOhm. The cyclic current–voltage curves featured a current rise at modifications of multilayer MWCNT structures. A PMC-based composition was the basis of a receptor element of an amperometric biosensor. The sensitivity of glucose detection by the biosensor was 0.30 and 0.05 μA/mM for PMCs/MWCNTs/GOx and PMCs/GOx compositions, respectively. The biosensor was insensitive to the presence of ethanol or citric acid in the sample. Polyelectrolyte microcapsules based on a multilayer membrane incorporating the enzyme and MWCNTs can be efficient in developing biosensors and microbial fuel cells.</jats:p>

Julian Tix, Jan-Niklas Hengsbach, Joshua Bode et al.

Microorganisms • 0

<jats:p>The fermentation of Actinobacillus succinogenes in bioelectrochemical systems offers a promising approach to enhance biotechnological succinate production by shifting the redox balance towards succinate and simultaneously enabling CO2 utilization. Key process parameters include the applied electric potential, electrode material, and reactor design. This study investigates the influence of various carbon fabric electrodes and applied potentials on product distribution during fermentation of A. succinogenes. Building on prior findings that potentials between −600 mV and –800 mV increase succinate production, recent data reveal that more negative potentials, beyond the water electrolysis threshold, trigger electrochemical side reactions, altering product yields. Specifically, succinate decreased from 19.76 ± 0.41 g∙L−1 to 14.1 ± 1.6 g∙L−1, while lactate rose from 0.59 ± 0.12 g∙L−1 to 3.12 ± 0.21 g∙L−1. Contrary to common assumptions, the shift is not primarily driven by oxygen formation. Instead, the results indicate that the intracellular redox potential is affected by both the applied potential and hydrogen evolution, which alters metabolic pathways to maintain redox balance. These findings demonstrate that more negative applied potentials in electro-fermentation processes can impair succinate yields, emphasizing the importance of fine-tuning electrochemical conditions in the system for optimized biotechnological succinate production.</jats:p>

Cristina Gutiérrez-Sánchez, Encarnación Lorenzo

Journal of The Electrochemical Society • 2022

<jats:p>Recently, continuous advances in the development of nanoporous surfaces and their modification with biomolecules, such as redox enzymes have made possible important biolectrochemical applications of these surfaces. New nanoporous surfaces have been designed with a very well controlled architecture that improves the properties of their flat counterparts, resulting in surfaces with a large specific surface area, high conductivity and better electrochemical activity, in particular with regard to increase specific surface area, conductivity and electrochemical activity. The challenge is to achieve suitable pore size, spatial arrangement and pore distribution to facilitate substrate transport and enzyme orientation. The objective is to obtain an ideal nanoporous surface that provides a large surface area, rapid mass transport of substrates and efficient immobilization of redox enzymes to obtain direct electron transfer (DET). Although the electron transfer between the redox centers of the enzyme and the electrode is achieved frequently in the presence of redox mediators, which is known as mediated electron transfer (MET). In this review the latest advances in gold and carbon nanoporous surfaces modified with oxidase enzymes in the development of enzymatic fuel cells or enzymatic biosensors are discussed.</jats:p>

Kristen E. Garcia, Sofia Babanova, William Scheffler et al.

Biotechnology and Bioengineering • 2016

<jats:title>ABSTRACT</jats:title><jats:sec><jats:label /><jats:p>The engineering of robust protein/nanomaterial interfaces is critical in the development of bioelectrocatalytic systems. We have used computational protein design to identify two amino acid mutations in the small laccase protein (SLAC) from <jats:italic>Streptomyces coelicolor</jats:italic> to introduce new inter‐protein disulfide bonds. The new dimeric interface introduced by these disulfide bonds in combination with the natural trimeric structure drive the self‐assembly of SLAC into functional aggregates. The mutations had a minimal effect on kinetic parameters, and the enzymatic assemblies exhibited an increased resistance to irreversible thermal denaturation. The SLAC assemblies were combined with single‐walled carbon nanotubes (SWNTs), and explored for use in oxygen reduction electrodes. The incorporation of SWNTs into the SLAC aggregates enabled operation at an elevated temperature and reduced the reaction overpotential. A current density of 1.1 mA/cm<jats:sup>2</jats:sup> at 0 V versus Ag/AgCl was achieved in an air‐breathing cathode system. Biotechnol. Bioeng. 2016;113: 2321–2327. © 2016 Wiley Periodicals, Inc.</jats:p></jats:sec>

Xuanye Leng, Siyu Chen, Samantha R. McCuskey et al.

Advanced Electronic Materials • 2024

<jats:title>Abstract</jats:title><jats:p>Bioelectrochemical systems (BES) have garnered significant attention for their applications in renewable energy, microbial fuel cells, biocatalysis, and bioelectronics. In BES, bioelectrodes are used to facilitate extracellular electron transfer among microbial biocatalysts. This study is focused on enhancing the efficiency of these processes through microcompartmentalization, a technique that strategically organizes and segregates microorganisms within the electrode, thereby bolstering BES output efficiency. The study introduces a deoxyribonucleic acid (DNA)‐based reduced graphene oxide (rGO) aerogel engineered as a bioanode to facilitate microorganism compartmentalization while providing an expanded biocompatible surface with continuous conductivity. The DNA‐rGO aerogel is synthesized through the self‐assembly of graphene oxide and DNA, with thermal reduction imparting lightweight structural stability and conductivity to the material. The DNA component serves as a hydrophilic framework, enabling precise regulation of compartment size and biofunctionalization of the rGO surface. To evaluate the performance of this aerogel bioanode, measurements of current generation are conducted using <jats:italic>Shewanella oneidensis MR‐1</jats:italic> bacteria as a model biocatalyst. The bioanode exhibits a current density reaching up to 1.5 A·m⁻<jats:sup>2</jats:sup>, surpassing the capabilities of many existing bioanodes. With its abundant microcompartments, the DNA‐rGO demonstrates high current generation performance, representing a sustainable approach for energy harvesting without reliance on metals, polymers, or heterostructures.</jats:p>

Izabella Kłodowska, Joanna Rodziewicz, Wojciech Janczukowicz et al.

Water • 0

<jats:p>Bioelectrochemical sequencing batch biofilm reactors (SBBRs) may be used as post-anoxic reactors. The aim of this study was to determine how nitrate removal depends on the type of external carbon source and the electric current density (J). The effect of citric acid and potassium bicarbonate on N removal efficiency and the denitrifying bacteria biofilm community at an electric current density of 105 and 210 mA/m2 was determined. Nitrogen removal efficiency depended on the density of the electric current and the carbon source. The highest efficiency of N removal was in the reactor with 210 mA/m2 and citric acid. Regardless of the J value, the addition of an external carbon source to the reactors resulted in a 4–6 fold increase in the relative number of denitrifying bacteria in the biomass in relation to the reactor operated without an electric current flow and organics in the influent. The highest number of denitrifiers was observed in the reactor with an inorganic carbon source and with a density of 105 mA/m2. The main factor determining the shifts in composition of the denitrifying bacteria was the electric current flow. In the reactors operated with the electric current flow, Thauera aminoaromatica MZ1T occurred in the reactors with potassium bicarbonate while Alicycliphilus denitrificans K601 preferred citric acid.</jats:p>

D. Nosek, A. Cydzik‐Kwiatkowska

Journal of Ecological Engineering • 2022

In recent years, much research has focused on energy recovery from biomass as an alternative to fossil fuel usage. Microbial fuel cells (MFCs), which produce electricity via microbial decomposition of organic matter, are of great interest. The performance of an MFC depends on the electrode material; most often, carbon materials with good electrical conductivity and durability are used. To increase the power output of an MFC, the anode material can be modified to reduce the internal resistance and increase the anode surface area. Therefore, this study determined how modifying a carbon felt anode with reduced graphene oxide (rGO) and a combination of rGO with iron (III) oxide (rGO-Fe) affected electricity generation in an MFC fueled with wastewater. A mixed microbial consor tium was used as the anode biocatalyst . The MFC-rGO-Fe produced significantly higher voltages than other cells (average 109.4 ± 75.1 mV in the cycle). Power density curves indicated that modifying the anode with rGO-Fe increased the power of the MFC to 4.5 mW/m 2 , 9.3- and 3.9-times higher than that of the control MFC and the MFC-rGO, respectively. Anode modification reduced the internal resistance of the cells from 1029 Ω in the control MFC to 370 and 290 Ω in the MFC-rGO and MFC-rGO-Fe, respectively. These results show that a mixture of rGO with iron (III) oxide positively affects electricity production and can be successfully used for anode modification in the MFCs fueled with wastewater.

Lizhen Zeng, Lixia Zhang

RSC Advances • 2025

A novel multilayer nanoflake structure of manganese oxide/graphene oxide (γ-MnO2/GO) was fabricated via a simple template-free chemical precipitation method, and the modified carbon felt (CF) electrode with γ-MnO2/GO composite was used as an anode material for microbial fuel cells (MFCs). The characterization results revealed that the γ-MnO2/GO composite has a novel multilayer nanoflake structure and offers a large specific surface area for bacterial adhesion. The electrochemical analyses demonstrated that the γ-MnO2/GO composite exhibited excellent electrocatalytic activity and enhanced the electrochemical reaction rate and reduced the electron transfer resistance, consequently facilitating extracellular electron transfer (EET) between the anode and bacteria. The maximum power density of MFC equipped with the γ-MnO2/GO composite-modified carbon felt anode was 1.13 ± 0.09 W m−2, which was 119% higher than that of the pure commercial carbon felt anode under the same conditions. Thus, the results demonstrate that the multilayer γ-MnO2/GO nanoflake composite-modified carbon felt anode is a promising anode material for high-performance MFC applications.

V. Fedina, A.A. Kovaleva, S. Alferov

XI Международная конференция молодых ученых: биоинформатиков, биотехнологов, биофизиков, вирусологов, молекулярных биологов и специалистов фундаментальной медицины — 2024 : сб. тез. • 2024

Biofuel cells are an actively developing technology that involves the use of living systems to generate electricity. In this work, membrane fractions of Gluconobacter oxydans bacteria were applied on electrodes modified with graphene oxide. The modification of graphite felt leads to an increase in its electrochemical properties, due to which the process of electron transfer between the electrode and the biocatalyst is increased.

Xinmin Liu, Zhaoxin Zhou, Ning Liu et al.

Environmental Technology • 2024

ABSTRACT A novel graphene oxide-modified resin (graphene oxide-macroporous adsorption resin) was prepared and used as a multifunctional carrier in an anaerobic fluidized bed microbial fuel cell (AFB-MFC) to treat phenolic wastewater (PW). The macroporous adsorption resin (MAR) was used as the carrier, graphene oxide was used as the modified material, the conductive modified resin was prepared by loading graphene oxide (GO) on the resin through chemical reduction. The modified resin particles were characterized by scanning electron microscopy (SEM), Raman spectroscopy (RS), specific surface area and pore structure analysis. Graphene oxide-macroporous adsorption resin special model was established using the Amorphous Cell module in Materials Studio (MS), and the formation mechanism of graphene oxide-macroporous adsorption resin was studied using mean square displacement (MSD) of the force module. Molecular dynamics simulation was used to study the motion law of molecular and atomic dynamics at the interface of graphene oxide-macroporous adsorption resin composites. The strong covalent bond between GO and MAR ensures the stability of GO/MAR. When the modified resin prepared in 3.0 mg/mL GO mixture was used in the AFB-MFC, the COD removal of wastewater was increased by 9.1% to 72.44%, the voltage was increased by 84.04% to 405.8 mV, and power density was increased by 765.44% to 242.67 mW/m2. GRAPHICAL ABSTRACT

Elitsa Chorbadzhiyska, Ivo Bardarov, Yolina Hubenova et al.

Catalysts • 0

<jats:p>In this study, graphite–metal oxide (Gr–MO) composites were produced and explored as potential anodic catalysts for microbial fuel cells. Fe2O3, Fe3O4, or Mn3O4 were used as a catalyst precursor. The morphology and structure of the fabricated materials were analyzed by scanning electron microscopy and X-ray diffraction, respectively, and their corrosion resistance was examined by linear voltammetry. The manufactured Gr–MO electrodes were tested at applied constant potential +0.2 V (vs. Ag/AgCl) in the presence of pure culture Pseudomonas putida 1046 used as a model biocatalyst. The obtained data showed that the applied poising resulted in a generation of anodic currents, which gradually increased during the long-term experiments, indicating a formation of electroactive biofilms on the electrode surfaces. All composite electrodes exhibited higher electrocatalytic activity compared to the non-modified graphite. The highest current density (ca. 100 mA.m−2), exceeding over eight-fold that with graphite, was achieved with Gr–Mn3O4. The additional analyses performed by cyclic voltammetry and electrochemical impedance spectroscopy supported the changes in the electrochemical activity and revealed substantial differences in the mechanism of current generation processes with the use of different catalysts.</jats:p>

Danielle T. Bennett, Anne S. Meyer

Applied and Environmental Microbiology • 2025

<jats:title>ABSTRACT</jats:title> <jats:sec> <jats:title/> <jats:p> <jats:italic>Shewanella oneidensis</jats:italic> ( <jats:italic>S. oneidensis</jats:italic> ) has the capacity to reduce electron acceptors within a medium and is thus used frequently in microbial fuel generation, pollutant breakdown, and nanoparticle fabrication. Microbial fuel setups, however, often require costly or labor-intensive components, thus making optimization of their performance onerous. For rapid optimization of setup conditions, a model reduction assay can be employed to allow simultaneous, large-scale experiments at lower cost and effort. Since <jats:italic>S. oneidensis</jats:italic> uses different extracellular electron transfer pathways depending on the electron acceptor, it is essential to use a reduction assay that mirrors the pathways employed in the microbial fuel system. For microbial fuel setups that use nanoparticles to stimulate electron transfer, reduction of graphene oxide provides a more accurate model than other commonly used assays as it is a bulk material that forms flocculates in solutions with a large ionic component. However, graphene oxide flocculates can interfere with traditional absorbance-based measurement techniques. This study introduces a novel image analysis method for quantifying graphene oxide reduction, showing improved performance and statistical accuracy over traditional methods. A comparative analysis shows that the image analysis method produces smaller errors between replicates and reveals more statistically significant differences between samples than traditional plate reader measurements under conditions causing graphene oxide flocculation. Image analysis can also detect reduction activity at earlier time points due to its use of larger solution volumes, enhancing color detection. These improvements in accuracy make image analysis a promising method for optimizing microbial fuel cells that use nanoparticles or bulk substrates. </jats:p> <jats:sec> <jats:title>IMPORTANCE</jats:title> <jats:p> <jats:italic>Shewanella oneidensis</jats:italic> ( <jats:italic>S. oneidensis</jats:italic> ) is widely used in reduction processes such as microbial fuel generation due to its capacity to reduce electron acceptors. Often, these setups are labor-intensive to operate and require days to produce results, so use of a model assay would reduce the time and expenses needed for optimization. Our research developed a novel digital analysis method for analysis of graphene oxide flocculates that may be utilized as a model assay for reduction platforms featuring nanoparticles. Use of this model reduction assay will enable rapid optimization and drive improvements in the microbial fuel generation sector. </jats:p> </jats:sec> </jats:sec>

Wu Hao, Sang-Hun Lee, Shaik Gouse Peera

Nanomaterials • 0

<jats:p>Current study provides a novel strategy to synthesize the nano-sized MnO nanoparticles from the quick, ascendable, sol-gel synthesis strategy. The MnO nanoparticles are supported on nitrogen-doped carbon derived from the cheap sustainable source. The resulting MnO/N-doped carbon catalysts developed in this study are systematically evaluated via several physicochemical and electrochemical characterizations. The physicochemical characterizations confirms that the crystalline MnO nanoparticles are successfully synthesized and are supported on N-doped carbons, ascertained from the X-ray diffraction and transmission electron microscopic studies. In addition, the developed MnO/N-doped carbon catalyst was also found to have adequate surface area and porosity, similar to the traditional Pt/C catalyst. Detailed investigations on the effect of the nitrogen precursor, heat treatment temperature, and N-doped carbon support on the ORR activity is established in 0.1 M of HClO4. It was found that the MnO/N-doped carbon catalysts showed enhanced ORR activity with a half-wave potential of 0.69 V vs. RHE, with nearly four electron transfers and excellent stability with just a loss of 10 mV after 20,000 potential cycles. When analyzed as an ORR catalyst in dual-chamber microbial fuel cells (DCMFC) with Nafion 117 membrane as the electrolyte, the MnO/N-doped carbon catalyst exhibited a volumetric power density of ~45 mW m2 and a 60% degradation of organic matter in 30 days of continuous operation.</jats:p>

Asim Ali Yaqoob, Albert Serrà, Showkat Ahmad Bhawani et al.

Polymers • 0

<jats:p>Although regarded as environmentally stable, bioelectrochemical fuel cells or, microbial fuel cells (MFCs) continue to face challenges with sustaining electron transport. In response, we examined the performance of two graphene composite-based anode electrodes—graphene oxide (GO) and GO–polymer–metal oxide (GO–PANI–Ag)—prepared from biomass and used in MFCs. Over 7 days of operation, GO energy efficiency peaked at 1.022 mW/m2 and GO–PANI–Ag at 2.09 mW/m2. We also tested how well the MFCs could remove heavy metal ions from synthetic wastewater, a secondary application of MFCs that offers considerable benefits. Overall, GO–PANI–Ag had a higher removal rate than GO, with 78.10% removal of Pb(II) and 80.25% removal of Cd(II). Material characterizations, electrochemical testing, and microbial testing conducted to validate the anodes performance confirmed that using new materials as electrodes in MFCs can be an attractive approach to improve the electron transportation. When used with a natural organic substrate (e.g., sugar cane juice), they also present fewer challenges. We also optimized different parameters to confirm the efficiency of the MFCs under various operating conditions. Considering those results, we discuss some lingering challenges and potential possibilities for MFCs.</jats:p>

Yuanfeng Liu, Tingli Ren, Zijing Su et al.

Journal of Materials Chemistry A • 0

<jats:p>Weak biofilm colonization and sluggish extracellular electron transfer (EET) between the biofilm and anode are major obstacles to achieving high power density in microbial fuel cells (MFCs).</jats:p>

Wenxian Guo, Meiqiong Chen, Xiaoqing Liu et al.

Chemistry – A European Journal • 2021

<jats:title>Abstract</jats:title><jats:p>A simple, cost‐effective strategy was developed to effectively improve the electron transfer efficiency as well as the power output of microbial fuel cells (MFCs) by decorating the commercial carbon paper (CP) anode with an advanced Mo<jats:sub>2</jats:sub>C/reduced graphene oxide (Mo<jats:sub>2</jats:sub>C/RGO) composite. Benefiting from the synergistic effects of the superior electrocatalytic activity of Mo<jats:sub>2</jats:sub>C, the high surface area, and prominent conductivity of RGO, the MFC equipped with this Mo<jats:sub>2</jats:sub>C/RGO composite yielded a remarkable output power density of 1747±37.6 mW m<jats:sup>−2</jats:sup>, which was considerably higher than that of CP‐MFC (926.8±6.3 mW m<jats:sup>−2</jats:sup>). Importantly, the composite also facilitated the formation of 3D hybrid biofilm and could effectively improve the bacteria–electrode interaction. These features resulted in an enhanced coulombic efficiency up 13.2 %, nearly one order of magnitude higher than that of the CP (1.2 %).</jats:p>

Yuyang Wang, Huan Yang, Jing Wang et al.

Coatings • 0

<jats:p>Microbial fuel cells (MFCs) have exhibited potential in energy recovery from waste. In this study, an MFC reactor with a polyaniline–sodium alginate–graphene oxide (PANI–SA–GO)/carbon brush (CB) hydrogel anode achieved maximum power density with 4970 mW/m3 and produced a corresponding current density of 4.66 A/m2, which was 2.72 times larger than the MFC equipped with a carbon felt film (CF) anode (1825 mW/m3). Scanning electron microscopy indicated that the PANI-SA-GO/CB composite anode had a three-dimensional macroporous structure. This structure had a large specific surface area, providing more sites for microbial growth and attachment. When the charging-discharging time was set from 60 min to 90 min, the stored charge of the PANI-SA-GO/CB hydrogel anode (6378.41 C/m2) was 15.08 times higher than that of the CF (423.05 C/m2). Thus, the mismatch between power supply and electricity consumption was addressed. This study provided a simple and environment-friendly modification method and allowed the prepared PANI–SA–GO/CB hydrogel anode to markedly promote the energy storage and output performance of the MFC.</jats:p>

Praveena Gangadharan, Indumathi M. Nambi, Jaganathan Senthilnathan et al.

RSC Advances • 0

<p>In the present study, a low molecular heterocyclic aminopyrazine (Apy)–reduced graphene oxide (r-GO) hybrid coated carbon cloth (r-GO–Apy–CC) was employed as an active and stable bio-electro catalyst in a microbial fuel cell (MFC).</p>

M. Al-badani, Peng Chong, Heng-Siong Lim

International Journal of Green Energy • 2023

ABSTRACT Microbial fuel cells (MFCs) have attracted much interest as an alternative energy conversion technology and as a system for recovering and treating wastewater. MFC is a powerful technique for generating energy from various sources, including natural organic matter and renewable biomass. It has several possible applications, including power generation for many small electronic devices, wastewater treatment, and biosensors. However, the restricted power output of MFCs is the most significant impediment to their widespread use and up-scaling in practical applications. The anode electrode is the most critical component of an MFC, where poor anode electrode performance leads to poor MFC efficiency. Therefore, efforts have been made to modify electrodes to improve their performance. While power density is an essential metric in determining MFC efficiency, other parameters such as Coulombic efficiency, current density, cell voltage, and the removal rate of chemical oxygen demand (COD) should also be considered to evaluate the performance of MFC. This study reviews the most recent electrode modification techniques through anode treatments with metal oxides, conductive polymers, carbon nanotubes, and other chemical compounds as well as through cathode modifications. Different modified MFCs are compared in terms of their power density and the type of bacteria and membrane used.

Sri Sathya Sandilya Garimella, Sai Vennela Rachakonda, Sai Sowmya Pratapa et al.

Annals of Microbiology • 2024

Microbial fuel cells (MFCs), which use bacterial electron transport mechanisms to generate energy, have become a viable technology for renewable energy production. This review investigates the evolutionary and functional connections between bacterial energy transduction mechanisms and mitochondrial electron transport chains, building on the endosymbiont theory of eukaryotic cell evolution. The conserved features and similarities between prokaryotic and eukaryotic electron transport pathways were elucidated, highlighting their common origins and roles in cellular bioenergetics. This discussion explores the essential mechanisms governing the movement of electrons and ions across biological membranes, crucial for generating energy and maintaining electrochemical gradients in bacteria and mitochondria. Capitalizing on these insights, we explore the applications of electrogenic bacteria in MFCs for renewable electricity generation. Optimal conditions for enhancing bacterial electron transfer to electrode surfaces are identified, paving the way for improved MFC performance. Potential large-scale implementations of MFCs in wastewater treatment, biosensing, and bioremediation of contaminated environments are discussed, underscoring their versatility and environmental benefits. The importance of investigating bioenergetic mechanisms at both the cellular and molecular scales of fully harnessing the capabilities of microbial energy conversion systems is highlighted in this review. By bridging the gap between fundamental cellular processes and sustainable technologies, we aim to advance renewable energy solutions that harness the remarkable capabilities of electrogenic microorganisms.

Akshat Sharma, Lara Đelević, Katharina Herkendell

Energy Technology • 2024

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.

Huajun Feng, Yuxiang Liang, K. Guo et al.

Environmental Science &amp; Technology Letters • 2016

Titanium has been widely used as a dimensionally stable anode in the electrolysis industry because of its excellent corrosion resistance, conductivity, and scalability. However, because of its poor biocompatibility and poor performance as a bioanode, it has drawn little attention in the field of microbial fuel cells (MFCs). This study reports an efficient way to convert a titanium electrode into a high-performance anode for MFCs, in situ growth of titanium dioxide nanotubes (TNs) on its surface. After TN modification, the titanium surface became rougher, more hydrophilic, and more conducive for anodic biofilm formation. The maximal current density achieved on this TN-modified titanium electrode was 12.7 A m–2, which was 190-fold higher than that of the bare titanium electrode and even higher than that of the most commonly used carbon felt electrode. Therefore, the high conductivity, corrosion resistance, and current density make the TN-modified titanium electrode a promising and scalable anode for MFCs.

Zejie Wang, B. Lim

Environmental Engineering Research • 2019

Sediment microbial fuel cells (SMFCs) illustrated great potential for powering environmental sensors and bioremediation of sediments. In the present study, array anodes for SMFCs were fabricated with graphite rods as anode material and stainless steel plate as electric current collector to make it inconvenient to in situ settle down and not feasible for large-scale application. The results demonstrated that maximum power of 89.4 μW was obtained from three graphite rods, twice of 43.3 μW for two graphite rods. Electrochemical impedance spectroscopy revealed that three graphite rods resulted in anodic resistance of 61.2 Ω, relative to 76.0 Ω of two graphite rods. It was probably caused by the parallel connection of the graphite rods, as well as more biomass which could reduce the charge transfer resistance of the biofilm anode. The presently designed array configuration possesses the advantages of easy to enlarge the surface area, decrease in anodic resistance because of the parallel connection of each graphite rod, and convenience to berry into sediment by gravity. Therefore, the as prepared array node would be an effective method to fabricate large-scale SMFC and make it easy to in situ applicate in natural sediments.

Wenbin Liu, Leiming Lin, Ying Meng et al.

Environmental Science: Nano • 2021

Microbial fuel cell with titanium dioxide nanotube array cathode was first demonstrated as a promising approach for uranium recovery and separation from groundwater.

Weihua He, Xiaoyuan Zhang, Jia Liu et al.

Environmental Science: Water Research &amp; Technology • 2016

A new type of scalable MFC was developed based on using alternating graphite fiber brush array anode modules and dual cathode modules in order to simplify construction, operation, and maintenance of the electrodes. The modular MFC design was tested with a single (two-sided) cathode module with a specific surface area of 29 m2 m−3 based on a total liquid volume (1.4 L; 20 m2 m−3 using the total reactor volume of 2 L), and two brush anode modules. Three different types of spacers were used in the cathode module to provide structural stability, and enhance air flow relative to previous cassette (combined anode–cathode) designs: a low-profile wire spacer; a rigid polycarbonate column spacer; and a flexible plastic mesh spacer. The best performance was obtained using the wire spacer that produced a maximum power density of 1100 ± 10 mW m−2 of cathode (32 ± 0.3 W m−3 based on liquid volume) with an acetate-amended wastewater (COD = 1010 ± 30 mg L−1), compared to 1010 ± 10 mW m−2 for the column and 650 ± 20 mW m−2 for the mesh spacers. Anode potentials were unaffected by the different types of spacers. Raw domestic wastewater produced a maximum of 400 ± 8 mW m−2 under fed batch conditions (wire-spacers), which is one of the highest power densities for this fuel. Over time the maximum power was reduced to 300 ± 10 mW m−2 and 275 ± 7 mW m−2 for the two anode compartments, with only slightly less power of 250 ± 20 mW m−2 obtained under continuous flow conditions. In fixed-resistance tests, the average COD removal was 57 ± 5% at a hydraulic retention time of 8 h. These results show that this modular MFC design can both simplify reactor construction and enable relatively high power generation from even relatively dilute wastewater.

Thorben Muddemann, Dennis Haupt, Bolong Jiang et al.

Processes • 0

<jats:p>This contribution describes the effect of the quality of the catalyst coating of cathodes for wastewater treatment by microbial fuel cells (MFC). The increase in coating quality led to a strong increase in MFC performance in terms of peak power density and long-term stability. This more uniform coating was realized by an airbrush coating method for applying a self-developed polymeric solution containing different catalysts (MnO2, MoS2, Co3O4). In addition to the possible automation of the presented coating, this method did not require a calcination step. A cathode coated with catalysts, for instance, MnO2/MoS2 (weight ratio 2:1), by airbrush method reached a peak and long-term power density of 320 and 200–240 mW/m2, respectively, in a two-chamber MFC. The long-term performance was approximately three times higher than a cathode with the same catalyst system but coated with the former paintbrush method on a smaller cathode surface area. This extraordinary increase in MFC performance confirmed the high impact of catalyst coating quality, which could be stronger than variations in catalyst concentration and composition, as well as in cathode surface area.</jats:p>

Tianjiao Guo, Chunyan Zhang, Jingkai Zhao et al.

Scientific Reports • 0

<jats:title>Abstract</jats:title><jats:p>A Chemical absorption-bioelectrochemical reduction (CABER) system is based on Chemical absorption-biological reduction (CABR) system, which aims at NO removal and has been studied in many of our previous works. In this paper, we applied polypyrrole (PPy) on the electrode of bioelectrochemical reactor (BER) of CABER system, which induced a much higher current density in the cyclic voltammetry (CV) curve for the electrode itself and better NO removal rate in the system. In addition, a Microbial Electrolysis Cell (MEC) is constructed to study its strengthening mechanism. Results shows that PPy-MEC has a greater Faraday efficiency and higher reduction rate of Fe(III)EDTA and Fe(II)EDTA-NO in the solution when compared to original Carbon MEC, which confirms the advantage of PPy-modified electrode(s) in the CABER system. The results of this study are reported for illustration of potential of CABER technology and design of low-cost high-efficiency NO<jats:sub><jats:italic>x</jats:italic></jats:sub> control equipment in the future.</jats:p>

Xiaolin Zhang, Xiaojing Li, Xiaodong Zhao et al.

RSC Advances • 0

<p>The great potential of bioelectrochemical systems (BESs) in pollution control combined with energy recovery has attracted increasing attention.</p>

Angela Cantillo-González, Javiera Anguita, Claudia Rojas et al.

Micromachines • 0

<jats:p>Bioelectrochemical systems (BESs) have been extensively studied for treatment and remediation. However, BESs have the potential to be used for the enrichment of microorganisms that could replace their natural electron donor or acceptor for an electrode. In this study, Winogradsky BES columns with As-rich sediments extracted from an Andean watershed were used as a strategy to enrich lithotrophic electrochemically active microorganisms (EAMs) on electrodes (i.e., cathodes). After 15 months, Winogradsky BESs registered power densities up to 650 μWcm−2. Scanning electron microscopy and linear sweep voltammetry confirmed microbial growth and electrochemical activity on cathodes. Pyrosequencing evidenced differences in bacterial composition between sediments from the field and cathodic biofilms. Six EAMs from genera Herbaspirillum, Ancylobacter, Rhodococcus, Methylobacterium, Sphingomonas, and Pseudomonas were isolated from cathodes using a lithoautotrophic As oxidizers culture medium. These results suggest that the tested Winogradsky BES columns result in an enrichment of electrochemically active As-oxidizing microorganisms. A bioelectrochemical boost of centenarian enrichment approaches, such as the Winogradsky column, represents a promising strategy for prospecting new EAMs linked with the biogeochemical cycles of different metals and metalloids.</jats:p>