Carbon Felt Anode Research Articles

Co-modified MoO2 nanoparticles highly dispersed on N-doped carbon nanorods as anode electrocatalyst of microbial fuel cells

Cobalt-modified molybdenum dioxide nanoparticles highly dispersed on nitrogen-doped carbon nanorods (Co–MoO2/NCND), are synthesized from anilinium trimolybdate dihydrate nanorods, for the performance improvement of microbial fuel cell based on a mixed bacterial culture. Electrochemical measurements demonstrate that the as-synthesized Co–MoO2/NCND exhibits excellent electrocatalytic activity for the charge transfer on anode, providing the cell with a maximum power density of 2.06 ± 0.05 W m−2, which is strikingly higher than the bare carbon felt anode (0.49 ± 0.04 W m−2). The excellent performance of Co–MoO2/NCND is ascribed to the increased electronic conductivity of carbon nanorods by N-doping, the high ability of MoO2 to enrich electroactive bacteria, as demonstrated by high-throughput sequencing, and the enhanced activity of MoO2 by Co-modifying toward redox reactions in electroactive bacteria. This report provides a new concept of anode electrocatalyst fabrications for the application of microbial fuel cells in electricity generation and wastewater treatment.

High performance yeast-based microbial fuel cells by surfactant-mediated gold nanoparticles grown atop a carbon felt anode

The behavior of gold nanoparticles grown atop a polyethyleneimine functionalized carbon felt substrate is explored for the first time. This green synthesis growth process utilizes surface-bound seeds and an exploration of the effect of a surfactant ligand mediator on the directional growth of the gold nanoparticles. Rough, irregularly shaped, and wide-spread gold nanoflower structures are developed from the seeds atop the hydrophilic functionalized carbon felt fibers through this process. Nanoparticle growth is acquired by the adaptation of a simple solution consisting of a gold salt reducer (L-ascorbic acid), nanoparticle initiator (chloroauric acid), and a strong ligand (4-mercaptobenzoic acid, MBA). Nanoparticle growth time and the concentration of the directional mediating surfactant MBA are varied to optimize the synthesis. The gold nanoparticle structures are examined through X-ray photoelectron spectroscopy and high-resolution scanning electron microscopy. Furthermore, the effects of attachment, biofilm formation, and coverage activity on the performance of a yeast-based microbial fuel cell are electrochemically evaluated. Results show both favorable and unfavorable conditions for yeast biofilm inhabitancy which are verified through electron microscopy, and a relationship between the surface chemical compositions, incomplete gold salt reduction, presence of residual sulphur, and effective yeast active-surface coverage on modified carbon felt is demonstrated. The best power density achieved was 2771 ± 569 mW·m−2 for the polyethyleneimine-modified carbon felt with gold nanoparticles prepared with 715 μM MBA for 30 min; a value higher than many benchmarks referenced in literature representing a new contribution to the field.

Selection of anodic material for the combined electrochemical-biological treatment of lindane polluted soil washing effluents

This paper focuses on the removal of lindane from soil washing effluents (SWEs) using combined electrochemical -biological processes. In particular, it has been evaluated the influence of the anodic material used in the electrolysis of the SWE on the biodegradability and toxicity of the effluents. Four anode materials were tested: Boron Doped Diamond (BDD), Carbon Felt (CF), and Mixed Metal Oxides Anodes with iridium and ruthenium (MMO-Ir and MMO-Ru). These materials were tested at different current densities and electric current charges applied. Lindane, TOC, sulphate, and chlorine species concentrations were monitored during electrochemical experiments, showing important differences in their evolution during the treatment. In spite of reaching a good removal of lindane with all the materials tested, results showed that Boron Doped Diamond working at 15 mA cm−2 achieved the best biodegradability results in the electrolyzed effluents, because the ratio BOD5/COD increased from 0.2 to 0.5, followed by Carbon Felt anode. Regarding toxicity, Carbon Felt decreased toxicity by 80%. Opposite to what it was expected, MMO anodes did not achieve biodegradability improvement and they only showed reduction in toxicity at high electrical charges.

Electrocatalytic Hydrogenation and Oxidation of 5-Hydroxymethylfurfural for Efficient Production of Biobased Monomers: A Paired Electrolyzer Approach

Electrochemical conversion of biorenewable compounds is a promising route for sustainable chemical production. Herein, we report a high efficiency for electrocatalytic conversion of 5-(hydroxymethyl)furfural (HMF) to two biobased monomers by pairing HMF reduction and oxidation reactions in a single electrochemical cell. HMF hydrogenation to 2,5-bis(hydroxymethyl)furan (BHMF) was achieved under mild electrolyte conditions (pH 9.2) over a Ag/C catalyst at the cathode. The selectivity and efficiency for Ag-catalyzed BHMF formation were sensitive to cathode potential, owing to competition from HMF hydrodimerization reactions and hydrogen evolution. Moreover, the carbon support of Ag/C was active for HMF reduction and contributed to undesired dimer formation at strong cathodic potentials. As a result, high BHMF selectivity and efficiency was only achieved within a narrow potential range near –1.3 V. At the anode, HMF oxidation to 2,5-furandicarboxylic acid (FDCA) with ~100% efficiency was achieved under the same conditions by a homogeneous redox mediator, 4-acetamido-TEMPO (ACT), together with an inexpensive carbon felt anode. Furtunately, the insensitive selectivity of ACT-mediated HMF oxidation anode potential allows HMF hydrogenation and oxidation reactions to perform together in a single electrochemical cell, which demonstrates high molar yields of BHMF and FDCA (86% and 96%, respectively) and a combined electron efficiency of 187%, which is nearly two-fold enhancement compared to the unpaired cells. Our recent progress in developing porous Ag electrode materials for electrochemical reduction will also be presented.

Three-dimensional high performance free-standing anode by one-step carbonization of pinecone in microbial fuel cells

In this paper, the free-standing macroporous carbon anode is prepared by one-step carbonization of pinecone without any further modification. The obtained anode is N, P-codoped porous carbon material, which is beneficial for electrochemical active bacterial adhesion and the fast start-up of cells. Both of the output voltage and long-term operation stability of the obtained anode are higher than that of carbon felt. The charge transfer resistance after biofilm formation is only 1.4 Ω, being 85.1% lower than that of carbon felt anode. 16S rRNA gene sequence analysis shows that Geobacter soli is the main electricigen and its ratio at the obtained anode is much higher than that at carbon felt (77.4% vs 34.0%). The N, P-codoped carbon as the three-dimensional free-standing anode has excellent electrochemical properties and is low cost and easy preparation. Most importantly, it enhances extracellular electron transfer, thus has potential application in microbial fuel cells.

Electro-irradiated technologies for clopyralid removal from soil washing effluents

In this work, electrolysis and electro-irradiated technologies, i.e. sonoelectrolysis, photoelectrolysis and photosonoelectrolysis have been evaluated in order to improve the biodegradability of soil washing effluents polluted with the herbicide clopyralid. Results obtained showed that simple electrolysis with carbon felt anodes improved the biodegradability of the effluent and that combination of electrolysis with irradiation technologies lead to very different operative results. Photoelectrolysis produced a synergistic effect in clopyralid removal and mineralization, while sonoelectrolysis and photosonoelectrolysis did not generate any positive effect, showing antagonisms. Regarding the biodegradability of the effluents, photoelectrolysis was the only technology which demonstrated a significant enhancement; nevertheless, it has associated an important energy consumption in comparison to simple electrolysis processes.

Applying the electrode potential slope method as a tool to quantitatively evaluate the performance of individual microbial electrolysis cell components

Improving the design of microbial electrolysis cells (MECs) requires better identification of the specific factors that limit performance. The contributions of the electrodes, solution, and membrane to internal resistance were quantified here using the newly-developed electrode potential slope (EPS) method. The largest portion of total internal resistance (120 ± 0 mΩ m2) was associated with the carbon felt anode (71 ± 5 mΩ m2, 59% of total), likely due to substrate and ion mass transfer limitations arising from stagnant fluid conditions and placement of the electrode against the anion exchange membrane. The anode resistance was followed by the solution (25 mΩ m2) and cathode (18 ± 2 mΩ m2) resistances, and a negligible membrane resistance. Wide adoption and application of the EPS method will enable direct comparison between the performance of the components of MECs with different solution characteristics, electrode size and spacing, reactor architecture, and operating conditions.

Iron and carbon granules added to anode enhanced the sludge decrement and electrical performance of sludge microbial fuel cell

Sludge microbial fuel cell (SMFC) can utilize the organics in sludge to generate power, and has attracted widespread attention. However, the low efficiency of organics utilization and limited power-output are the main challenges that need to be addressed. This study proposed an in situ method without additional energy to enhance the performance of SMFC by adding the package of iron and carbon granules (FeC). In the reactors including FeC-SMFC (the FeC package placed under the carbon felt anode and separated from the closed-circuit), FeC-OSMFC (FeC-SMFC in open-circuit), and FeCSMFC (the FeC package attached to the anodic bottom and closed-circuit), the degradation of refractory organics especially humic acid-like substances was significantly promoted, due to the FeC micro-electrolysis at neutral pH. More organics were beneficial for the enrichment of typical exoelectrogens belonging to Proteobacteria and Firmicutes, thereby improving the electrical performance of FeC-SMFC and FeCSMFC, compared with normal SMFC without FeC package (NSMFC). In FeCSMFC, the soluble and total chemical oxygen demand removal efficiencies were 65.60% and 52.64%. The removal efficiency of volatile suspended solids in FeCSMFC was 69.26%, which was 30.05%, 14.97%, 9.87% and 6.62% higher than that in open-circuit SMFC, NSMFC, FeC-OSMFC and FeC-SMFC, respectively. The power output of FeCSMFC was 37.28 W m−3, 6.06 and 1.76 times higher than that of NSMFC and FeC-SMFC, respectively. The addition of FeC package to anode is a cost-saving and effective method to enhance electricity generation and sludge decrement of SMFC.

Improving Electrochemical Performance of Carbon Felt Anode by Modifying With Akaganeite in Marine Benthic Microbial Fuel Cells

AbstractEnhancing the electrochemical performance of anode is a critical step for improving the power output of marine benthic microbial fuel cells (BMFCs). An active anode involving the akaganeite (β‐FeOOH)‐coated carbon felt was proposed in present study. Results showed that electrochemical performance of modified anode was significantly improved. The peak current density of oxidation reaction increased from 0.664 to 6.107 A m−2. The exchange current density was improved from 11.75 × 10−3 to 151.36 × 10−3 mA cm−2. Electron transfer resistance decreased from 13.4 to 1.407 Ω, while the surface capacitance dramatically increased. The maximum power density of the BMFCs equipped with modified anode approached to 504.2 mW m−2, 2.3 times higher than that with unmodified anode. Moreover, relative abundance of dissimilatory iron reducing bacteria (DIRB) on the modified anode increased. Finally, a molecule synergetic mechanism containing electrostatic interaction and bacteria recognition between DIRB and β‐FeOOH was proposed to interpret the improvement of modified anode.

Synergic degradation of 2,4,6-trichlorophenol in microbial fuel cells with intimately coupled photocatalytic-electrogenic anode

A microbial fuel cell system with intimately coupled photocatalytic-electrogenic anode (photocatalytic-MFC) was proposed for the synergetic degradation of 2,4,6-trichlorophenol (2,4,6-TCP) which has a structure of three chlorine groups connecting to a phenol ring and is well recognized as a recalcitrant pollutant for its high toxicity, bioaccumulation and persistence. The photocatalytic-electrogenic anode was prepared by coating mpg-C3N4 on a carbon felt anode, followed by inoculating with municipal sewage and acclimating with 2,4,6-TCP at gradient concentrations. Improved TCP degradation was achieved, showing 79.3% of TCP removal in 10 h with an original concentration of 200 mg L−1, which was higher than that obtained with the unilluminated MFC (66.0%) and the photocatalytic-only process (56.1%). The coupled photocatalytic-electrogenic process demonstrated different degradation pathways compared with the photocatalytic-only process, with one open-chain compound (2-chloro-4-keto-2-hexenedioic acid, 2-CMA) detected in the photocatalytic-MFC system. Microbial community analysis revealed that Pseudomonas, instead of Geobacter observed in the unilluminated MFC bioanode, dominated in the photocatalytic-electrogenic anode MFC biofilm, which might be responsible for enhanced current generation in the coupled system. In addition, biofilm rich with Rhodococcus on air-cathode was also responsible for the enhanced TCP removal. This research provides an efficient strategy for the treatment of wastewater with recalcitrant contaminants by intimate-coupling of the photocatalytic and the electrogenic processes.

Carbon felt molecular modification and biofilm augmentation via quorum sensing approach in yeast-based microbial fuel cells

Yeast from the species S. cerevisiae can naturally secrete three quorum sensing (QS) molecules in a certain ratio to regulate metabolism and cellular growth, and to exchange with the surrounding medium. Phenylethanol and tryptophol are considered the predominant QS molecular components with tyrosol being the third. In this work, each of these three QS molecules are separately immobilized, for the first time, onto carbon felt anodes (CF) with polyethyleneimine (PEI) to ascertain the chemical modification of the surface and to enhance the biofilm formation, activity, and conductivity for the direct electron transfer (DET) in yeast-based microbial fuel cells (MFCs). The cyclic voltammetry and electrochemical impedance spectroscopy results suggest that this modification with QS molecules can improve the formation of the biofilm and is very useful for electron transfer mobility. From optical inspection, the biofilm formed inside the felts is relatively more distributed between the fibers, homogenous, and has significant coverage. MFCs adopting CF-PEI/Phenylethanol and CF-PEI/Tryptophol have similar maximum power density (MPD) at 159.46 ± 10.68 mW·m−2 and 156.57 ± 5.84 mW·m−2. The yeast biofilm is attached only on the surface of single fibers when tyrosol is immobilized on CF-PEI, which partially explains having the lowest MPD, 135.56 ± 3.79 mW·m−2. In conclusion, phenylethanol and tryptophol are suggested as the more effective QS molecules whereas tyrosol reduces the absolute amount of sessile biofilm even though the biofilm is still more conductive.

Enhanced performance of microbial fuel cells by electrospinning carbon nanofibers hybrid carbon nanotubes composite anode

A novel carboxylated multiwalled carbon nanotubes/carbon nanofibers (CNTs/CNFs) composite electrode was fabricated by electrospinning. Heat pressing process was applied to improve the interconnection of fiber aggregates, mechanical stability and reduce the contact resistance. Optimal dose of carbon nanotubes was selected to fabricate the anode in microbial fuel cells after comparing with plain electrospinning CNFs anode and commercial carbon felt (CF) anode. As a result, the optimal anode delivered a maximum power density of 362 ± 20 mW m−2, which is 110%, 122% higher than that of carbon nanofibers and carbon felt anodes. Cyclic voltammograms, Tafel and electrochemical impedance spectroscopy tests also verified that the prepared electrode has largest catalytic current (148 μA cm−2) and exchange current density i0 (6.3 × 10−5 A cm−2), as well as smallest internal resistance (∼40 Ω). The as-prepared anode exhibited a better conductivity, excellent biocompatibility, good hydrophilicity and superior electrocatalytic activity, which was not only beneficial to the attachment and reproduction of microorganisms, but also promoted extracellular electron transfer between bacteria cells and the anode. This result shows that electrospinning has a promising perspective in fabricating high performance electrodes for microbial fuel cells.

A fluid dynamics perspective on material selection in microbial fuel cell-based biosensors

This work proposes a novel approach to investigate the behavior of single chamber microbial fuel cells (SCMFCs) based sensors by implementing fluid dynamic simulations to especially investigate the role of diffusion phenomena. When different flow rates are applied (i.e., 25 mL/h and 100 mL/h) the electrolyte flows differently into the cell, changing its speed and the drift-area (Adrift) in which the fluid/electrolyte is directly pushed during the drift process. Asymmetric squared SCMFCs (a-SCMFCs) ensure optimal fluid motion thanks to their architecture that maximizes the drift-area. In this work a-SCMFCs are tested as acetate bio-sensors using carbon paper and carbon felt as anodes. Experimental results show that the behavior of a-SCMFCs-based sodium acetate biosensors is strongly influenced by the morphology of both carbon felt and carbon paper-based anodes. We used fluid dynamics simulations implementing both the drift and the diffusion processes to gain new information on the behavior of carbon paper and carbon felt anodes. We especially investigated the role of their porosity, in determining the actual fluid distribution and analyte concentration inside the device, at the surface of the porous material and into its volume. We demonstrate that less porous materials, as carbon paper, are more adequate to be used in single chamber MFC-based biosensors. Indeed they can favor an optimal fluid motion, especially favoring more uniform diffusion phenomena and interaction between biofilm and surface than corrugates surfaces, as those characterizing carbon felt, resulting in a more effective analyte conversion and signal transduction.

Facile preparation of binder-free NiO/MnO2-carbon felt anode to enhance electricity generation and dye wastewater degradation performances of microbial fuel cell

Binder-free NiO/MnO2-carbon felt electrode is prepared with a facile two-step hydrothermal method. The NiO self-grown on the carbon felt is used as the skeleton structure to support the in-situ growth of MnO2. Both the core and shell materials are excellent pseudocapacitance materials. The compositing of such pseudocapacitance metal oxides can produce synergistic effects, so that the modified electrode has a high capacitance. NiO/MnO2-carbon felt electrode also possesses a high specific surface area, super hydrophilicity and good biocompatibility, which are conducive to the enrichment of typical exoelectrogen Geobacter. As the anode, NiO/MnO2-carbon felt electrode can effectively improve the electricity generation and methyl orange (MO) wastewater degradation performances of microbial fuel cell (MFC). The highest output voltage and the maximum power density of MFC with NiO/MnO2-carbon felt anode are respectively 652 mV and 628 mW m−2, which are much higher than those of MFC with MnO2-carbon felt anode (613 mV, 544 mW m−2), NiO-carbon felt anode (504 mV, 197 mW m−2) and unmodified carbon felt anode (423 mV, 162 mW m−2). The decolourization efficiency and the chemical oxygen demand (COD) removal rate of MO for MFC with NiO/MnO2-carbon felt anode are respectively 92.5% and 58.2% at 48 h.

Effects of biochar anodes in rice plant microbial fuel cells on the production of bioelectricity, biomass, and methane

This study investigated the potential benefits of using biochar granules as an alternative to the standard carbon felt anode in microbial fuel cells (MFC). Single-chamber cylindrical air-cathode MFCs were filled with sandy loam soil. Rice plants (Oryza sativa L.) cultivar FARO 44 were grown in plant MFCs (PMFCs). The performance of PMFC was compared with that of the soil MFC (SMFC) lacking rice plants. During 125 days of operation, the highest power density was 41.41 mW m−2 of cathode area and it was observed in PMFC with carbon felt anode (PMFC-RCF). In PMFC with biochar anode (PMFC-RBC), the power density was lower, and the highest value recorded was 11.11 mW m−2. On average (over the 125 days), PMFCs and SMFCs equipped with biochar anodes produced less bioelectricity, 16 and 27 percent, respectively, of those equipped with carbon felt anodes. On the other hand, methane emissions from PMFCS and SMFCs equipped with biochar anodes were reduced by 39% and 19%, respectively, when compared to those with carbon felt anodes. It was also observed that the total plant biomass was not significantly affected by the types of anode used. More studies are required to further improve the bioelectricity production of MFCs incorporated with biochar knowing that they have the benefit of reducing methane emission without decreasing the plant biomass yield.

Quick start-up and performance of microbial fuel cell enhanced with a polydiallyldimethylammonium chloride modified carbon felt anode

It is of significant importance to simultaneously shorten the start-up time and enhance the electricity generation performance for practical application of microbial fuel cell (MFC). In this paper, the polydiallyldimethylammonium chloride (PDDA) modified carbon felt (PDDA-CF) electrode was prepared and used as the anode of PDDA-MFC. The anode significantly enhanced the start-up speed and electricity generation and dye wastewater degradation performances of the PDDA-MFC. The start-up time of PDDA-MFC is only 9 h, which is only 7.5% that of the unmodified carbon felt anode MFC (CF-MFC). The charge transfer resistance, the maximum output voltage and the maximum output power density of PDDA-MFC were 9.7 Ω, 741 mV and 537.8 mW m-2 respectively, which were 70.3% lower than, 1.7 times and 3.3 times greater than those of CF-MFC respectively. In addition, the color and chemical oxygen demand (COD) removal rates of Reactive Brilliant Red X-3B for PDDA-MFC reached 95.94% and 64.24% at 24 h respectively, which were 41.5% and 51.2% higher than those of CF-MFC respectively. Due to the electrostatic attraction of PDDA, the adhesion and metabolic mass transfer rate of exoelectrogens are accelerated, thus the PDDA-CF electrode has excellent electrochemical properties and bio-affinity. This paper provides a new idea to enhance the start-up speed and performance of MFC simultaneously.

Self-standing Electrochemical Set-up to Enrich Anode-respiring Bacteria On-site.

Anaerobic respiration coupled with electron transport to insoluble minerals (referred to as extracellular electron transport [EET]) is thought to be critical for microbial energy production and persistence in many subsurface environments, especially those lacking soluble terminal electron acceptors. While EET-capable microbes have been successfully isolated from various environments, the diversity of bacteria capable of EET is still poorly understood, especially in difficult-to-sample, low energy or extreme environments, such as many subsurface ecosystems. Here, we describe an on-site electrochemical system to enrich EET-capable bacteria using an anode as a respiratory terminal electron acceptor. This anode is connectedto a cathode capable ofcatalyzing abiotic oxygen reduction. Comparing this approach with electrocultivation methods that use a potentiostat for poising the electrode potential, the two-electrode system does not require an external power source. We present an example of our on-site enrichment utilized in an alkaline pond at the Cedars, a terrestrial serpentinization site in Northern California. Prior attempts to cultivate mineral reducing bacteria were unsuccessful, which is likely due to the low-biomass nature of this site and/or the low relative abundance of metal reducing microbes. Prior to implementing our two-electrode enrichment, we measured the vertical profile of dissolved oxygen concentration. This allowed us to place the carbon felt anode and platinum-electroplated carbon felt cathode at depths that would support anaerobic and aerobic processes, respectively. Following on-site incubation, we further enriched the anodic electrode in the laboratory and confirmeda distinct microbial community compared to the surface-attached or biofilm communities normally observed at the Cedars. This enrichment subsequently led to the isolation of the first electrogenic microbe from the Cedars. This method of on-site microbial enrichment has the potential to greatly enhance the isolation of EET-capable bacteria from low biomass or difficult to sample habitats.

Efficient Production of Biorenewable Monomers from Paired Electrocatalytic Hydrogenation and Oxidation of 5-(Hydroxymethyl)Furfural

Electrochemical synthesis is a promising route for sustainable chemical production; however, its widespread application is hindered by low reaction rates and high energy demands. In this presentation, we report the efficient electrocatalytic conversion of 5-(hydroxymethyl)furfural (HMF) to biobased monomers by pairing HMF reduction and oxidation half-reactions in a single electrochemical cell. HMF hydrogenation to 2,5-bis(hydroxymethyl)furan (BHMF) was achieved at mild pH and ambient temperature using a self-synthesized Ag/C cathode catalyst. Meanwhile, HMF oxidation to 2,5-furandicarboxylic acid (FDCA) was facilitated with close to 100% faradaic efficiency using an inexpensive carbon felt anode together with a homogeneous nitroxyl radical catalyst. The selectivity and faradaic efficiency for Ag-catalyzed BHMF formation were sensitive to cathode potential, owing to competition from HMF hydrodimerization reactions and water reduction (hydrogen evolution). Moreover, the carbon support of Ag/C was active for HMF reduction and contributed to undesired dimer/oligomer formation at strongly cathodic potentials. As a result, high BHMF selectivity and efficiency were only achieved within a narrow potential range. Fortunately, the selectivity of nitroxyl-mediated HMF oxidation was not dependent on anode potential, thus allowing HMF hydrogenation and oxidation half-reactions to be performed together in a single cathode-potential-controlled cell. Electrocatalytic HMF conversion in the paired cell achieved high yields of BHMF and FDCA, and nearly two-fold greater overall electron efficiency compared to the unpaired cells. Future research will focus on the design of continuous-flow electrochemical reactors, in which the use of membrane electrode assemblies (MEA) may significantly lower internal resistance and further reduce total energy demands.

Enhancing extracellular electron transfer efficiency and bioelectricity production by vapor polymerization Poly (3,4-ethylenedioxythiophene)/MnO2 hybrid anode

Electron transfer efficiency in electroactive biofilm is the limiting factor for bioelectricity output of bioelectrochemical system. Here, carbon felt (CF) is coated with manganese dioxide (MnO2) which acts as electron mediator in electroactive biofilm. A wrapping layer of conducting Poly 3,4-ethylenedioxythiophene is developed to protect the MnO2 and enhance electron transfer efficiency of MnO2 mediator. The hybrid bioanode (PEDOT/MnO2/CF bioanode) delivered the highest electron transfer efficiency (6.3 × 10−9 mol cm−2 s−1/2) and the highest capacitance of 4.78 F, much higher than bare CF bioanode (1.50 ± 0.04 × 10−9 mol cm−2 s−1/2 and 0.42 F). As a result, microbial fuel cells could produce a maximum power density of 1534 ± 13 mW m−2, approximately 57.7% higher than that with the bare carbon felt anode (972 ± 21 mW m−2). Possible mechanisms are proposed to help understanding the different function of the PEDOT and MnO2 on the anodic layer. This study introduces an effective method for the fabrication of high performance anode.

Microbial fuel cells equipped with an iron-plated carbon-felt anode and Shewanella oneidensis MR-1 with corn steep liquor as a fuel

A single chamber type microbial fuel cell (MFC) with 100mL of chamber volume and 50cm2 of air-cathode was developed in this study wherein a developed iron-plated carbon-felt anode and Shewanella oneidensis MR-1 were used. The performance of the iron-plated carbon-felt anode and the possibility of corn steep liquor (CSL) as a fuel, which was the byproduct of corn wet milling and contained lactic acid, was investigated here. MFCs equipped with iron-plated or non-plated carbon-felt anodes exhibited maximum current densities of 443 or 302mA/m2 using 10g/L of reagent-grade lactic acid, respectively. In addition, using centrifuged CSL without insoluble ingredients or non-centrifuged CSL as a fuel, the maximum current densities of the MFCs with iron-plated carbon-felt anode were 321 or 158mA/m2, respectively. This report demonstrated the effect of iron-plated carbon-felt anode for electricity generation of MFC using S.oneidensis MR-1 and the performance of CSL as a fuel.