Reneta Boukoureshtlieva, Toma Stankulov, Anton Momchilov

Ecological Engineering and Environment Protection • 2021

<jats:p>In the past 20 years Microbial fuel cells (MFCs) have been extensively studied regarding the possibility of transforming organic waste directly into electricity. There are significant differences between MFCs and conventional low temperature Fuel Cells (FCs), which make MFCs attractive: biotic catalyst at the anode; the anodic fuel is complex organic waste; MFCs operate under mild reaction conditions (neutral pH, temperature and pressure), close to ambient levels as optimum. Like chemical fuel cells, MFCs are composed of anode and cathode. Oxygen is an ideal electron acceptor for MFCs because of its high redox potential, availability, and sustainability. However, the Oxygen Reduction Reaction (ORR) is kinetically sluggish, resulting in a large proportion of potential loss. Also, working conditions are quite different because of the type of complex media in which MFCs operate. In order to overcome these limitations, catalysts are often used to lower the overpotentials and accelerate the kinetics of the oxygen reduction reaction. One of the main challenges is the development of efficient and stable cathode catalysts for MFCs. By far, Pt and Pt-based catalysts (PGMs) have been extensively used, due to their catalytic efficiency in gas-diffusion electrodes. But the high cost and low durability have significantly lowered their utilization in MFCs. A variety of non-precious metal catalysts have been developed for MFC applications including carbon-based catalysts, carbon supported composite catalysts, Me-based catalysts and biocatalysts. It is supposed that the ORR catalyst used for wastewater treatment in MFCs is simple to synthesize, cost-effective, durable after long-term operation in wastewater, tolerant to poisoning and able to restore catalytic activity after cleaning. In this regard carbon-based catalyst may be the most promising candidate for practical applications. This study reviews different carbon-based ORR catalysts for MFC applications for wastewater treatment and energy recovery.</jats:p>

Ying Chao

MATEC Web of Conferences • 2025

<jats:p>The integration of microbial fuel cells (MFCs) with biomass waste utilization presents a promising pathway for simultaneous energy recovery and environmental remediation. MFCs generate electricity by harnessing the metabolic activity of electroactive microorganisms, which oxidize organic substrates and transfer electrons to an external circuit. This review investigates the operational principles of MFCs, core system components, and their capacity to convert diverse biomass-derived substrates—including agricultural residues, food waste, and industrial wastewater—into electrical energy. Pretreatment techniques such as mechanical reduction and irradiation are discussed for improving substrate bioavailability and enhancing power density. The technical and economic feasibility of MFCs is evaluated, highlighting current limitations such as low energy output, material costs, and scale-up challenges. Additionally, the role of MFCs in carbon fixation and circular bioeconomy models is examined, demonstrating their potential to reduce greenhouse gas emissions while recovering valuable resources. Despite unresolved engineering and microbial constraints, ongoing advances in materials science, system architecture, and microbial engineering are expected to enhance the scalability and efficiency of MFC-based waste-to-energy platforms. This review underscores the importance of further interdisciplinary research to realize the full potential of MFCs in sustainable energy and waste management systems.</jats:p>

Yu-Chen Liu, Yu-Hsuan Hung, Shih-Fu Liu et al.

Sustainable Energy &amp; Fuels • 0

<p>The MFCs with N-MWCNT@GONR and MWCNT@GONR anodes exhibits high power densities up to 3444 mW m⁻² and 3291 mW m⁻².</p>

Leena R, Arya Sethu Madhavan, Lineesh M Kunjappan

ECS Meeting Abstracts • 2021

<jats:p> Melatonin(N-acetyl-5-methoxy tryptamine) is a paracrine hormone secreted by pineal gland in the brain. This endogenous hormone has the ability to maintain the body circadian rhythm.<jats:sup>1 </jats:sup>3,4-dihydroxy-L-phenylalanine (L-Dopa) is the intermediate precursor of the Neurotransmitter dopamine. L-dopa, as one of catecholamines, is widely used as a source of dopamine in the treatment of Parkinson’s disease and epilepsy.<jats:sup>2</jats:sup> </jats:p> <jats:p>Here, we report a sensor based on Platinum electrode modified with hydrothermally synthesized RGO and spinel nanoferrate for the simultaneous determination of L-Dopa and Melatonin.</jats:p> <jats:p>Graphene oxide (GO)is a graphene derived material with oxygen containing functional groups. Graphene is a material with honey comb like structure of carbon atoms having sp<jats:sup>2</jats:sup> bonding character. It exhibits high electrical conductivity, thermal conductivity and mechanical strength. GO containing functional groups like –OH, -COOH etc., acts as the site for the nucleation of metal oxide nanoparticles. It improves direct electron transfer between the electrode and the redox species by accelerating the electron transfer and enlarging the effective surface area.<jats:sup>3</jats:sup> GO was synthesized by modified Hummers method. Chemically converted graphene RGO has been prepared by various reduction methods such as chemical, microwave, electrochemical, thermal, solvothermal/hydrothermal, by reducing its oxygen content.<jats:sup>4</jats:sup> Green synthetic pathway of hydrothermal method was adopted for RGO synthesis to avoid hazardous chemical species and vigorous reaction conditions. Spinel ferrate like Copper Cobalt ferrate (CuCoFe<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub>) was synthesized by sol-gel method and RGO/Spinel nanocomposite was prepared by physical mixing.<jats:sup>5</jats:sup> The synthesized materials were characterized using various techniques like FTIR, XRD, FESEM etc. The electro catalytic activity of RGO/Spinel nanocomposite anchored platinum electrode for the simultaneous determination of melatonin and L-Dopa was studied using several voltammetric techniques. Bare platinum electrode was able to sense melatonin and L-Dopa both individually, but not simultaneously. Compared to RGO modified Platinum electrode, RGO-Spinel ferrate/Pt electrode exhibited good response in terms of lower potential of electrooxidation of L-Dopa and Melatonin with enhanced catalytic current with a peak separation of 0.48V. This enhancement in electrochemical performance is due to the increase in surface area as well as conductivity of the electrode upon modification with RGO-spinel nanocomposite which act as an excellent electrochemical oxidant for L-Dopa and melatonin.</jats:p> <jats:p> <jats:bold>References:</jats:bold> <jats:list list-type="roman-lower"> <jats:list-item> <jats:p>Levent, A.<jats:italic>J. Diam. Relat. Mater.</jats:italic> <jats:bold>2012</jats:bold>, 21, 114-119</jats:p> </jats:list-item> <jats:list-item> <jats:p>Yan, X.; Pan, D.; Wang, H.; Bo, X.; Guo, L.<jats:italic>J. Electroanal. Chem.</jats:italic> <jats:bold>2011</jats:bold>, 663, 36-42</jats:p> </jats:list-item> <jats:list-item> <jats:p>Pei, S.; Zhao, J.; Du, J.; Ren, W.; Cheng, H.<jats:italic>J. Carbon.</jats:italic> <jats:bold>2010</jats:bold>, 48, 4466-4474</jats:p> </jats:list-item> <jats:list-item> <jats:p>Luo, D.; Zhang, G.; Liu, J.; Sun, X.<jats:italic>J. Phys. Chem. C.</jats:italic> <jats:bold>2011</jats:bold>, 115, 11327-11335</jats:p> </jats:list-item> <jats:list-item> <jats:p>Elkholy, A. E.; Heakal, F. E.; Allam, K. A.<jats:italic>J. RSC Adv.</jats:italic> <jats:bold>2017</jats:bold>, 7, 51888</jats:p> </jats:list-item> </jats:list> </jats:p>

Leena R, Arya Sethu M

ECS Meeting Abstracts • 2020

<jats:p> Melatonin(N-acetyl-5-methoxy tryptamine) is a paracrine hormone secreted by pineal gland in the brain. This endogenous hormone has the ability to maintain the body circadian rhythm.<jats:sup>1 </jats:sup>3,4-dihydroxy-L-phenylalanine (L-Dopa) is the intermediate precursor of the neurotransmitter dopamine. L-dopa,as one of catecholamines, is widely used as a source of dopamine in the treatment of Parkinson’s disease and epilepsy.<jats:sup>2</jats:sup> </jats:p> <jats:p>Here, we report a sensor based on Platinum electrode modified with hydrothermally synthesised RGO and spinel nano ferrate for the simultaneous determination of L-Dopa and Melatonin.</jats:p> <jats:p>Graphene oxide (GO)is a graphene derived material with oxygen containing functional groups. Graphene is a material with honey comb like structure of carbon atoms having sp<jats:sup>2</jats:sup> bonding character. It exhibits high electrical conductivity, thermal conductivity and mechanical strength.GO containing functional groups like –OH, -COOH etc., acts as the site for the nucleation of metal oxide nano particles.It improves direct electron transfer between the electrode and the redox species by accelerating the electron transfer and enlarging the effective surface area.<jats:sup>3</jats:sup> GO was synthesized by modified Hummers method. Reduced graphene oxide (RGO) has been prepared by various reduction methods such as chemical, microwave, electrochemical, thermal, solvothermal, hydrothermal etc by reducing its oxygen content.<jats:sup>4</jats:sup> We employed a green synthetic pathway of hydrothermal method for RGO synthesis to avoid hazardous chemical species and vigorous reaction conditions. Copper Cobalt ferrate (CuCoFe<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub>) which is a spinel nanocomposite was synthesised by sol-gel method and RGO/Spinel nanocomposite was prepared by physical mixing.<jats:sup>5</jats:sup> The prepared RGO spinel nanocomposite was characterized by using various techniques like FTIR, XRD, SEM-EDAX etc.The electrocatalytic activity of RGO/Spinel nanocomposite anchored platinum electrode for the simultaneous determination of melatonin and L-Dopa was studied using several voltammetric techniques. Bare platinum electrode was able to sense melatonin and L-Dopa both individually, but not simultaneously. Compared to RGO modified Platinum electrode, RGO-Spinel ferrate/Pt electrode exhibited good response in terms of lower potential of electrooxidation of L-Dopa and melatonin with enhanced catalytic current with a peak separation of 0.48V. The simultaneous square wave voltammetric determination of L-Dopa and melatonin on RGO modified Platinum electrode and RGO-Spinel ferrate/Pt electrode are shown in Fig. 1. This enhancement in electrochemical performance is due to the increase in surface area as well as conductivity of the platinum electrode upon modification of RGO with spinel nanocomposite which act as an excellent electrochemical oxidant for L-Dopa and melatonin.</jats:p> <jats:p> <jats:bold>References:</jats:bold> </jats:p> <jats:p>1. Levent, A.,<jats:italic> Diam. Relat. Mater., </jats:italic> <jats:bold>2012</jats:bold>, 21, 114-119.</jats:p> <jats:p>2. Yan, X.; Pan, D.; Wang, H.; Bo, X.; Guo, L., <jats:italic>J. Electroanal. Chem., </jats:italic> <jats:bold>2011</jats:bold>, 663, 36-42.</jats:p> <jats:p>3. Pei, S.; Zhao, J.; Du, J.; Ren, W.; Cheng, H., <jats:italic>Carbon, </jats:italic> <jats:bold>2010</jats:bold>, 48, 4466-4474.</jats:p> <jats:p>4. Luo, D.; Zhang, G.; Liu, J.; Sun, X., <jats:italic>J. Phys. Chem. C, </jats:italic> <jats:bold>2011</jats:bold>, 115, 11327-11335.</jats:p> <jats:p>5. Elkholy, A. E.; Heakal, F. E.; Allam, K. A., <jats:italic>RSC Adv.,</jats:italic> <jats:bold>2017</jats:bold>, 7, 51888.</jats:p> <jats:p> <jats:inline-formula> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="1961fig1.jpg" xlink:type="simple"/> </jats:inline-formula> </jats:p> <jats:p>Figure 1</jats:p> <jats:p/>

Myoung Eun Lee, Yongtae Ahn, Seung Gu Shin et al.

Energies • 0

<jats:p>Anaerobic digestion (AD) can produce renewable energy and reduce carbon emissions, but the energy conversion efficiency is still limited in some waste streams. This study tested the effect of applied voltage removal for microbial electrolysis cells (MECs) treating primary sewage sludge. Two MECs were operated in parallel: a MEC-0.3 V with an applied voltage of 0.3 V and a MEC-OCV with open circuit voltage. Both reactors were inoculated with seed sludge originating from a MEC at 0.3 V applied voltage, and three batch cycles were operated for 36 d. The methane production of the MEC-OCV was 3759 mL/L in the first cycle and 2759 mL/L in the second cycle, which was similar (105% and 103%, respectively) to that of the MEC-0.3 V. However, in the third cycle, the methane production of the MEC-OCV (1762 mL/L) was 38.8% lower than that of the MEC-0.3 V (4545 mL/L). The methane contents in the biogas were 68.6–74.2% from the MEC-OCV, comparable to those from the MEC-0.3 V (66.6–71.1%). These results indicate that not only the MEC-0.3V but also the MEC-OCV outperformed AD in terms of methane yield and productivity, and the promotion using MEC-derived inoculum persisted equally with the MEC-OCV for two batch cycles after removing the applied voltage. Therefore, a MEC operation with cycled power supply may be beneficial in reducing the electric energy usage and improving the biogas production performance, compared to conventional AD.</jats:p>

Jerry Huayang Tang

IOP Conference Series: Earth and Environmental Science • 2021

<jats:title>Abstract</jats:title> <jats:p>Microbial electrolysis cells (MECs) represent a renewable hydrogen production technology that offers the possibility of converting wastewater to hydrogen through a bioelectrochemical process. Particularly, the MEC substrate has a significant effect on the performance of MECs, and in this review, the performances of over 30 substrates examined since 2015 are summarized and compared. It was evident that popular MEC substrates include dark fermentation effluents, pyrolysis products, and raw wastewaters. Additionally, the different MEC substrates investigated yielded different MEC performances, indicating that further studies are required before MECs can become a mature technology for up-scale applications.</jats:p>

E. Chorbadzhiyska, I. Bardarov, Y. Hubenova et al.

Bulgarian Chemical Communications • 2019

<jats:p>Microbial electrolysis cell (MEC) is an ecologically clean and innovative technology for hydrogen production. The development of cost-effective cathodes with high catalytic activity for hydrogen evolution reaction (HER) in nearneutral electrolytes is the most critical challenge for the practical application of MEC technology. In this study, graphite electrodes, functionalized with non-noble metal oxides, were produced and after electrochemical pre-treatment investigated as potential cathodes for MEC. The morphology of the developed materials was analyzed by scanning electron microscopy (SEM). Their electrochemical performance in neutral phosphate buffer solution (PBS) was explored by means of linear sweep voltammetry (LSV) and chronoamperometry (CA). The results from both methods show that all modified electrodes exhibit higher electrocatalytic activity towards HER than that of bare graphite, which is a prerequisite for further evaluation of these materials as cathodes in real MEC.</jats:p>

Marie Abadikhah, Miguel de Celis Rodriguez, Frank Persson et al.

Frontiers in Microbiology • 0

<jats:p>In single-chamber microbial electrolysis cells (MECs), organic compounds are oxidized at the anode, liberating electrons that are used for hydrogen evolution at the cathode. Microbial communities on the anode and cathode surfaces and in the bulk liquid determine the function of the MEC. The communities are complex, and their assembly processes are poorly understood. We investigated MEC performance and community composition in nine MECs with a carbon cloth anode and a cathode of carbon nanoparticles, titanium, or stainless steel. Differences in lag time during the startup of replicate MECs suggested that the initial colonization by electrogenic bacteria was stochastic. A network analysis revealed negative correlations between different putatively electrogenic <jats:italic>Deltaproteobacteria</jats:italic> on the anode. Proximity to the conductive anode surface is important for electrogens, so the competition for space could explain the observed negative correlations. The cathode communities were dominated by hydrogen-utilizing taxa such as <jats:italic>Methanobacterium</jats:italic> and had a much lower proportion of negative correlations than the anodes. This could be explained by the diffusion of hydrogen throughout the cathode biofilms, reducing the need to compete for space.</jats:p>

Aliya Temirbekova, Zhanar Tekebayeva, Aslan Temirkhanov et al.

Biology • 0

<jats:p>Natural resources are in short supply, and the ecosystem is being damaged as a result of the overuse of fossil fuels. The creation of novel technology is greatly desired for investigating renewable and sustainable energy sources. Microorganisms have received a lot of interest recently for their potential to transform organic waste into sustainable energy and high-value goods. New exoelectrogens that can transmit electrons to electrodes and remove specific wastewater contaminants are expected to be studied. In this study, we examined three distinct samples (as determined by chemical oxygen demand and pH) that can be used as anolytes to generate power in single-chamber and double-chamber microbial fuel cells using graphite electrodes. Wastewater from poultry farms was studied as an exoelectrogenic anolyte for microbial fuel cell power generation. The study examined 10 different bacterial strains, numbered A1 through A10. Due to their highly anticipated capacity to metabolize organic/inorganic chemicals, the diverse range of microorganisms found in poultry wastewater inspired us to investigate the viability of generating electricity using microbial fuel cells. From the investigated bacterial strains, the highest voltage outputs were produced by strains A1 (Lysinibacillus sphaericus) and A2 (Bacillus cereus), respectively, at 402 mV and 350 mV. Among the 10 different bacterial strains, strain A6 generated the least amount of electricity, measuring 35.03 mV. Furthermore, a maximum power density of 16.16 1.02 mW/m2 was achieved by the microbial fuel cell using strain A1, significantly outperforming the microbial fuel cell using a sterile medium. The strain A2 showed significant current and power densities of 35 1.12 mA/m2 and 12.25 1.05 mW/m2, respectively. Moreover, in the two representative strains, chemical oxygen demand removal and Coulombic efficiency were noted. Samples from the effluent anode chamber were taken in order to gauge the effectiveness of chemical oxygen demand removal. Wastewater had an initial chemical oxygen demand content of 350 mg/L on average. Strains A1 and A2 decomposed 94.28% and 91.71%, respectively, of the organic substrate, according to the chemical oxygen demand removal efficiency values after 72 h. Strains A1 and A2 had electron donor oxidation efficiencies for 72 h of 54.1% and 60.67%, respectively. The Coulombic efficiency increased as the chemical oxygen demand decreased, indicating greater microbial electroactivity. With representative strains A1 and A2, Coulombic efficiencies of 10% and 3.5%, respectively, were obtained in the microbial fuel cell. The findings of this study greatly advance the field as a viable source of power technology for alternative energy in the future, which is important given the depletion of natural resources.</jats:p>

Weilu Yang, Hexing Han, Minghua Zhou et al.

RSC Advances • 0

<p>A novel continuous flow electrosorption driven by microbial fuel cells (MFCs) was developed for the first time to remove tetracycline, the second most commonly used antibiotic, from synthetic wastewater.</p>

Vajihe Yousefi, Davod Mohebbi-Kalhori, Abdolreza Samimi et al.

International Journal of Hydrogen Energy • 2016

Remisha S R, Reshmi R, Sanmathi K R

International Journal of Advanced Research in Science, Communication and Technology • 0

<jats:p>The contamination of industrial wastewater with heavy metals poses a severe environmental and public health concern. Traditional methods of heavy metal removal often prove costly and environmentally unsustainable. In this context, microbial strategies have emerged as a promising and eco-friendly approach for effective heavy metal remediation from industrial wastewater. Microorganisms, including bacteria, fungi, and algae, have developed various mechanisms to withstand and sequester heavy metals from their surroundings. This review explores the diverse microbial strategies employed in heavy metal removal, encompassing biosorption, bioaccumulation, bioprecipitation, and bioleaching. These strategies exploit microbial cell surfaces, extracellular polymeric substances, and intracellular compartments to immobilize, transform, or release heavy metals. Moreover, recent advancements in genetic engineering and biotechnology have enabled the development of tailored microbial strains with enhanced metal-removal capabilities. The application of these engineered microbes, as well as naturally occurring strains, in bioremediation processes is discussed. This review also delves into the factors influencing microbial metal removal efficiency, such as pH, temperature, metal concentration, and co-existing contaminants. Additionally, the potential drawbacks and limitations of microbial strategies, including biomass disposal and long-term performance, are addressed. As heavy metal pollution continues to be a pressing global issue, understanding and harnessing microbial strategies for heavy metal removal from industrial wastewater holds significant promise for sustainable and cost-effective remediation practices. Integrating microbial processes into existing treatment methods can offer innovative solutions to mitigate the environmental impact of heavy metal contamination, thereby safeguarding ecosystems and public health</jats:p>

Dong-Mei Piao, Young-Chae Song, Dong-Hoon Kim

Energies • 0

<jats:p>This study demonstrated the enhancement of biogenic coal conversion to methane in a bioelectrochemical anaerobic reactor with polarized electrodes. The electrode with 1.0 V polarization increased the methane yield of coal to 52.5 mL/g lignite, which is the highest value reported to the best of our knowledge. The electrode with 2.0 V polarization shortened the adaptation time for methane production from coal, although the methane yield was slightly less than that of the 1.0 V electrode. After the methane production from coal in the bioelectrochemical reactor, the hydrolysis product, soluble organic residue, was still above 3600 mg chemical oxygen demand (COD)/L. The hydrolysis product has a substrate inhibition effect and inhibited further conversion of coal to methane. The dilution of the hydrolysis product mitigates the substrate inhibition to methane production, and a 5.7-fold dilution inhibited the methane conversion rate by 50%. An additional methane yield of 55.3 mL/g lignite was obtained when the hydrolysis product was diluted 10-fold in the anaerobic toxicity test. The biogenic conversion of coal to methane was significantly improved by the polarization of the electrode in the bioelectrochemical anaerobic reactor, and the dilution of the hydrolysis product further improved the methane yield.</jats:p>

Brittany Newell, Jose Garcia, Gary Krutz

Actuators • 0

<jats:p>Dielectric electroactive polymer materials represent a distinct group of smart materials that are capable of converting between electrical and mechanical energy. This research focuses on the modeling and testing of an industrial grade fluoropolymer material for its feasibility as a dielectric elastomer electroactive polymer. Through this process, a novel chemical pre-strain method was tested, along with a one-step process for application of pre-strain and addition of an elastomer conductive layer. Modeled and experimental actuators produced approximately 1 mm displacements with 0.625 W of electrical power. The displacement of the actuators was characterized, and the effects of multiple parameters were modeled and analyzed.</jats:p>

Erin M. Gaffney, Olja Simoska, Shelley D. Minteer

Biosensors • 0

<jats:p>Halophilic bacteria are remarkable organisms that have evolved strategies to survive in high saline concentrations. These bacteria offer many advances for microbial-based biotechnologies and are commonly used for industrial processes such as compatible solute synthesis, biofuel production, and other microbial processes that occur in high saline environments. Using halophilic bacteria in electrochemical systems offers enhanced stability and applications in extreme environments where common electroactive microorganisms would not survive. Incorporating halophilic bacteria into microbial fuel cells has become of particular interest for renewable energy generation and self-powered biosensing since many wastewaters can contain fluctuating and high saline concentrations. In this perspective, we highlight the evolutionary mechanisms of halophilic microorganisms, review their application in microbial electrochemical sensing, and offer future perspectives and directions in using halophilic electroactive microorganisms for high saline biosensing.</jats:p>

Arkadiy I. Garber, Kenneth H. Nealson, Nancy Merino

Frontiers in Microbiology • 0

<jats:p>Multi-heme cytochromes (MHCs), together with accessory proteins like porins and periplasmic cytochromes, enable microbes to transport electrons between the cytoplasmic membrane and extracellular substrates (e.g., minerals, electrodes, other cells). Extracellular electron transfer (EET) has been described in multiple systems; yet, the broad phylogenetic and mechanistic diversity of these pathways is less clear. One commonality in EET-capable systems is the involvement of MHCs, in the form of porin-cytochrome complexes, pili-like cytochrome polymers, and lipid-anchored extracellular cytochromes. Here, we put forth MHCscan—a software tool for identifying MHCs and identifying potential EET capability. Using MHCscan, we scanned ~60,000 bacterial and 2,000 archaeal assemblies, and identify a diversity of MHCs, many of which represent enzymes with no known function, and many found within organisms not previously known to be electroactive. In total, our scan identified ~1,400 unique enzymes, each encoding more than 10 heme-binding motifs. In our analysis, we also find evidence for modularity and flexibility in MHC-dependent EET pathways, and suggest that MHCs may be far more common than previously recognized, with many facets yet to be discovered. We present MHCscan as a lightweight and user-friendly software tool that is freely available: <jats:ext-link>https://github.com/Arkadiy-Garber/MHCscan</jats:ext-link>.</jats:p>

Shan-Wei Li, Guo-Ping Sheng, Yuan-Yuan Cheng et al.

Scientific Reports • 0

<jats:title>Abstract</jats:title><jats:p>Although the capacity for electroactive bacteria to convert environmental metallic minerals and organic pollutants is well known, the role of the redox properties of microbial extracellular polymeric substances (EPS) in this process is poorly understood. In this work, the redox properties of EPS from two widely present electroactive bacterial strains (<jats:italic>Shewanella oneidensis</jats:italic> and <jats:italic>Pseudomonas putida</jats:italic>) were explored. Electrochemical analysis demonstrates that the EPS extracted from the two strains exhibited redox properties. Spectroelectrochemical and protein electrophoresis analyses indicate that the extracted EPS from <jats:italic>S. oneidensis</jats:italic> and <jats:italic>P. putida</jats:italic> contained heme-binding proteins, which were identified as the possible redox components in the EPS. The results of heme-mediated behavior of EPS may provide an insight into the important roles of EPS in electroactive bacteria to maximize their redox capability for biogeochemical cycling, environmental bioremediation and wastewater treatment.</jats:p>

Robin Bonné, Koen Wouters, Jamie J. M. Lustermans et al.

Frontiers in Microbiology • 0

<jats:p>The global production of unrecycled electronic waste is extensively growing each year, urging the search for alternatives in biodegradable electronic materials. Electroactive bacteria and their nanowires have emerged as a new route toward electronic biological materials (e-biologics). Recent studies on electron transport in cable bacteria—filamentous, multicellular electroactive bacteria—showed centimeter long electron transport in an organized conductive fiber structure with high conductivities and remarkable intrinsic electrical properties. In this work we give a brief overview of the recent advances in biodegradable electronics with a focus on the use of biomaterials and electroactive bacteria, and with special attention for cable bacteria. We investigate the potential of cable bacteria in this field, as we compare the intrinsic electrical properties of cable bacteria to organic and inorganic electronic materials. Based on their intrinsic electrical properties, we show cable bacteria filaments to have great potential as for instance interconnects and transistor channels in a new generation of bioelectronics. Together with other biomaterials and electroactive bacteria they open electrifying routes toward a new generation of biodegradable electronics.</jats:p>

Min-Hua Cui, Dan Cui, Hyung-Sool Lee et al.

Scientific Reports • 0

<jats:title>Abstract</jats:title><jats:p>In this study, two modes of hybrid anaerobic digestion (AD) bioreactor with built-in BESs (electrodes installed in liquid phase (R1) and sludge phase (R2)) were tested for identifying the effect of electrodes position on azo dye wastewater treatment. Alizarin yellow R (AYR) was used as a model dye. Decolorization efficiency of R1 was 90.41 ± 6.20% at influent loading rate of 800 g-AYR/ m<jats:sup>3</jats:sup>·d, which was 39% higher than that of R2. The contribution of bioelectrochemical reduction to AYR decolorization (16.23 ± 1.86% for R1 versus 22.24 ± 2.14% for R2) implied that although azo dye was mainly removed in sludge zone, BES further improved the effluent quality, especially for R1 where electrodes were installed in liquid phase. The microbial communities in the electrode biofilms (dominant by <jats:italic>Enterobacter)</jats:italic> and sludge (dominant by <jats:italic>Enterococcus)</jats:italic> were well distinguished in R1, but they were similar in R2. These results suggest that electrodes installed in liquid phase in the anaerobic hybrid system are more efficient than that in sludge phase for azo dye removal, which give great inspirations for the application of AD-BES hybrid process for various refractory wastewaters treatment.</jats:p>

Patricia M. Olmos Moya, Silvia Gutiérrez Granados, Fethi Bedioui et al.

Electroanalysis • 2020

<jats:title>Abstract</jats:title><jats:p>An amperometric biosensor for the sensitive detection of superoxide was designed utilizing a drop‐coating approach for immobilizing the superoxide dismutase enzyme on Pt electrode modified with a thin layer of poly (3,4‐ethylenedioxythiophene) (PEDOT). The <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/elan201900396-math-0001.png" xlink:title="urn:x-wiley:10400397:media:elan201900396:elan201900396-math-0001" /> layer electrodeposited on Pt was characterized by cyclic voltammetry and atomic force microscopy (AFM). Then, drop‐coating procedure was chosen for the immobilization of superoxide dismutase (SOD), which was incorporated at the electrode surface using a solution containing SOD, glutaraldehyde and bovine serum albumin (optimized composition: <jats:italic>SOD 0.1 % – BSA 2 % – GA 2.5 %</jats:italic>.) This simple procedure allows forming a reproducible enzymatic biocomposite layer that allows optimal sensitivity and limit of detection for superoxide sensing. The synergistic effect integrates an effective conductivity and permselectivity attributed to the PEDOT layer, as well as the specificity and selectivity of SOD for the detection of superoxide. A high sensitivity (0.82±0.01 μA/μM) and a low detection limit of 11 nM were obtained, as well as good selectivity against main interfering biological compounds such as uric acid and ascorbic acid. Our results suggest that the biosensor could be used for the detection and quantification of <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/elan201900396-math-0002.png" xlink:title="urn:x-wiley:10400397:media:elan201900396:elan201900396-math-0002" /> <jats:italic>in vitro</jats:italic> and <jats:italic>in vivo</jats:italic>.</jats:p>

Andreea Madalina Pandele, Corina Andronescu, Adi Ghebaur et al.

Materials • 0

<jats:p>A high number of studies support the use of mesoporous silica nanoparticles (MSN) as carriers for drug delivery systems due to its high biocompatibility both in vitro and in vivo, its large surface area, controlled pore size and, more than this, its good excretion capacity from the body. In this work we attempt to establish the optimal encapsulation parameters of benzalkonium chloride (BZC) into MSN and further study its drug release. The influence of different parameters towards the drug loading in MSN such as pH, contact time and temperature were considered. The adsorption mechanism of the drug has been determined by using the equilibrium data. The modification process was proved using several methods such as Fourier transform-infrared (FT-IR), ultraviolet-visible (UV-VIS), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). Since MSN shows a lower drug release amount due to the agglomeration tendency, in order to increase MSN dispersion and drug release amount from MSN, two common biocompatible and biodegradable polymers were used as polymer matrix in which the MSN-BZC can be dispersed. The drug release profile of the MSN-BZC and of the synthesized hybrid materials were studied both in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). Polymer-MSN-BZC hybrid materials exhibit a higher drug release percent than the pure MSN-BZC when a higher dispersion is achieved. The dispersion of MSN into the hybrid materials was pointed out in scanning electron microscope (SEM) images. The release mechanism was determined using four mathematic models including first-order, Higuchi, Korsmeyer–Peppas and Weibull.</jats:p>

Miroslav Kvíčala, Michaela Štamborská, Jaromír Drápala

Applied Mechanics and Materials • 0

<jats:p>This paper is dedicated to the development and optimization of the porous titanium materials suitable for biomedical usage in traumatology. Main aim of the presented research activities is focused on preparation of biocompatible titanium based materials with controlled porosity. It was found that titanium specimens with total porosity approximately 40 % revealed mechanical properties very similar to those of human cortical bone. Two-layer specimens with controlled porosity were prepared and tested by electron microscopy for post-sintering cracks. All tested specimens with controlled porosity were cracks free. Future works will include preparation of geometrically more complicated shapes, machining and<jats:italic>in vitro</jats:italic>cells proliferation testing.</jats:p>

Mohammad Luqman, Saeed Alqaed, Fahad Awjah Almehmadi et al.

Journal of Electroanalytical Chemistry • 2024

Yanuar Rohmat Aji Pradana, Firhan Ahmad Fanani, Aminnudin Aminnudin et al.

Key Engineering Materials • 0

<jats:p>Subsequent processing through machining for biocompatible Zr-based BMG previously developed is needed in order to enlarge the material application, especially for medical devices. In this study the performance of CuCr tool on EDM process was investigated to cut biocompatible Zr-based BMG having low machinability nature. The experiment utilized volume loss technique to measure the TWR and consecutive SEM observation to reveal the tool wear mechanism of selected tool samples. The tool wear behavior was strongly characterized by the combination of discharge current and pulse-on time, where the larger TWR obtained by higher current and shorter pulse-on time. By SEM analysis, the irregular-shaped surface morphology with the presence of debris was observed on the tool wear region resulted by high discharge energy process. Additionally, the larger crater size, microvoids and numerous debris particles were also appeared on BMG workpiece surface machined using higher discharge energy.</jats:p>

Hindatu Yusuf, M. Suffian M. Annuar, Syed Mohammad Daniel Syed Mohamed et al.

Chemical Engineering Communications • 2019

Mohan Qin, Ibrahim M. Abu-Reesh, Zhen He

Water Research • 2016

Harsha Nagar, N. Badhrachalam, V.V. Basava Rao et al.

Materials Chemistry and Physics • 2019

R. M. Alonso, M. I. San-Martín, A. Sotres et al.

Scientific Reports • 0

<jats:title>Abstract</jats:title><jats:p>This study seeks to assess the impact that the anodic electrodeposition of graphene oxide (GO) has on the start-up process and on the development of microbial communities on the anode of BESs. The GO electrodeposited electrodes were characterised in abiotic conditions to verify the extent of the modification and were then transferred to a bioelectrochemical reactor. Results showed that the modified electrode allowed for a reduced start-up time compared to the control electrode. After three months, high throughput sequencing was performed, revealing that electrochemically reduced graphene oxide acts as a selective agent toward exoelectrogenic bacteria as <jats:italic>Geobacter</jats:italic>. Overall, this study shows that GO modified electrodes enhance biofilm build up in BES.</jats:p>

Vijay Jaswal, Rajesh Banu J, Yogalakshmi K. N.

SSRN Electronic Journal • 0

Sevi Murugavel

ECS Meeting Abstracts • 2023

<jats:p> The development of new and novel electrode materials for energy storage devices has become the intensive research by the materials science community because of its importance in the portable electronic devices, hybrid electric vehicles and many other applications. Since the discovery by Goodenough and his co-workers on the electrochemical behavior of olivine LiFePO<jats:sub>4</jats:sub> (LFP), different theoretical and experimental investigations have been undertaken to optimize it as cathode material in lithium-ion batteries and trying to understand the charge/discharge mechanism. Despite having many fascinating electrochemical properties, the main drawback of LFP lies with its low gravimetric density and poor electrical conductivity (both electronic and ionic) which limits the lithium intercalation/deintercalation rates, and hence the practical specific capacity. Therefore, it becomes necessary to gain the fundamental understanding of electronic structure of the LFP system by adopting appropriate experimental technique. We exploit the combined Mössbauer and X-ray absorption spectroscopy to unravel the electronic structure and local site symmetry of Fe in olivine structured LFP with different crystallite sizes (CS). The lattice parameters are found to contract with decrease in CS monotonously, whereas the electronic structural parameters exhibit two different regions with threshold anomaly around ≈30 nm CS. The <jats:sup>57</jats:sup>Fe Mössbauer studies reveal the coexistence of Fe<jats:sup>2+</jats:sup> and Fe<jats:sup>3+</jats:sup>sites and their relative concentration are mainly determined by the CS, which provides the comprehensive insight into the electronic structure of LFP at mesoscopic level. The soft X-ray absorption unravels unequivocally the valance states of Fe 3d electrons in the proximity of Fermi level, which are prone to the local lattice distortion. An obtained spectra fingerprint the effect of CS supplying rich information on valence state of iron, lithium-ion vacancy concentration, covalency and crystal field. The unique structural and electronic properties of the LFP are closely interlinked with changes in the bonding character, which shows the strong dependency on the CS. The evolution of the 3d states is in overall agreement with the local lattice distortion and provides the origin of the size effects on the electronic structure olivine phosphate and other transition metal ion containing materials. We observe polaronic conductivity enhancement of approximately two orders of magnitude at the nanoscale level as compared with its bulk counterpart. The volumetric changes with respect to crystallite size are related to the compressive strain resulting into the improvement in the electronic diffusivity. The nano-crystalline LFP with better kinetics will open the new avenue for its usage as cathode material in rechargeable batteries. </jats:p>

Carolina del Real Mata, Roozbeh Siavash Moakhar, Sara Mahshid

ECS Meeting Abstracts • 2020

<jats:p> Hydrogen peroxide (H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>) acts as a critical second messenger in fundamental biological processes, which makes it a highly important target for direct detection in biological systems. Among various read-out techniques, photoelectrochemical (PEC) sensing offers a low limit of detection and high sensitivity. Here, a promising, non-enzymatic, sunlight-driven, simple photoelectrochemical (PEC) sensor for H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> detection is presented. The electrode is based on a Si wafer, a thick ZnO spacer, a thin Au layer and a graphene layer on top. The fabrication was done through conventional e-beam evaporation deposition technique for the spacer and metal film. An additional layer of graphene was drop-casted on top. The latter provides highly conductive scaffolds to ease electron transport and to increase the electrode sensitivity. The morphological characteristics and optical properties were investigated via FESEM and UV-Vis spectroscopy, respectively. Additionally, the electrochemical characterization was conducted using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry. Direct detection of H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> was studied via chronoamperometry method under simulated sunlight by using a three-electrode configuration in which stainless-steel served as both counter and reference electrodes and the fabricated electrode as the working electrode. The photo responses to gold and gold/graphene electrodes in a non-enzymatic and biocompatible PBS environment with a pH 7.2 were thoroughly investigated. The gold-graphene demonstrates boosted properties combining excellent photoelectroactivity and high sensitivity towards H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> with a superb limit of detection of 1pM in a linear range of 1pM-100mM.</jats:p> <jats:p> <jats:bold>Keywords</jats:bold>: Hydrogen peroxide, gold, graphene, photoelectrochemical sensor </jats:p>

Takafumi Kato, Takuya Yoda, Naoki Yoshihara

Chemistry Letters • 2022

<jats:title>Abstract</jats:title> <jats:p>Biomass-derived carbon materials have attracted interest as metal-free electrode candidates for electrochemical reactions. Hydrocarbon formation (i.e., methane and ethane) using the electrochemical reduction of carbon dioxide (CO2ER) on as-synthesized sulfur (S) containing lignin derived carbon electrodes was demonstrated. The current efficiencies of hydrocarbon products by CO2ER were found to be dependent on the carbonized temperature and a thermal treatment scheme, resulting in different surface structures and chemical composition of S species.</jats:p>

Sandipam Srikanth, Yolanda Alvarez‐Gallego, Karolien Vanbroekhoven et al.

ChemPhysChem • 2017

<jats:title>Abstract</jats:title><jats:p>The enzymatic electrosynthesis of formic acid from the reduction of carbon dioxide (CO<jats:sub>2</jats:sub>) by using formate dehydrogenase (FDH) as a catalyst at the cathode in both its free and immobilized forms was studied in detail in a bioelectrochemical system (BES). The essential role of solubilizing CO<jats:sub>2</jats:sub> for its conversion was also studied by adding carbonic anhydrase (CA) to the FDH enzyme in both its free and immobilized forms. FDH alone in the free form showed large variation in the reduction current [(−6.2±3.9) A m<jats:sup>−2</jats:sup>], whereas the immobilized form showed less variation [(−3.8±0.5) A m<jats:sup>−2</jats:sup>] due to increased enzyme stability. The addition of CA with FDH increased the consumption of the current in both forms due to the fact that it allowed rapid dissolution of CO<jats:sub>2</jats:sub>, which made it available for the catalytic reaction with FDH. Remarkably, stable consumption of the current was observed throughout the operation if both CA and FDH were immobilized onto the electrode [(−3.9±0.2) A m<jats:sup>−2</jats:sup>]. Product formation by the immobilized enzyme was also continued for three repetitive cycles, which revealed the longevity of the enzyme after immobilization. The recyclability of NADH (NAD=nicotinamide adenine dinucleotide) was also clearly evidenced on the derivative voltammetric signature. Extension of this study for continuous and long‐term operation may reveal more possibilities for the rapid capture and conversion of CO<jats:sub>2</jats:sub>.</jats:p>

Nhlanganiso Ivan Madondo, Sudesh Rathilal, Babatunde Femi Bakare et al.

International Journal of Molecular Sciences • 0

<jats:p>The interspecies electron transfer (IET) between microbes and archaea is the key to how the anaerobic digestion process performs. However, renewable energy technology that utilizes the application of a bioelectrochemical system together with anaerobic additives such as magnetite-nanoparticles can promote both direct interspecies electron transfer (DIET) as well as indirect interspecies electron transfer (IIET). This has several advantages, including higher removal of toxic pollutants present in municipal wastewater, higher biomass to renewable energy conversion, and greater electrochemical efficiencies. This review explores the synergistic influence of bioelectrochemical systems and anaerobic additives on the anaerobic digestion of complex substrates such as sewage sludge. The review discussions present the mechanisms and limitations of the conventional anaerobic digestion process. In addition, the applicability of additives in syntrophic, metabolic, catalytic, enzymatic, and cation exchange activities of the anaerobic digestion process are highlighted. The synergistic effect of bio-additives and operational factors of the bioelectrochemical system is explored. It is elucidated that a bioelectrochemical system coupled with nanomaterial additives can increase biogas–methane potential compared to anaerobic digestion. Therefore, the prospects of a bioelectrochemical system for wastewater require research attention.</jats:p>

Yilkal Dessie, Sisay Tadesse

Sensing and Bio-Sensing Research • 2022

Sweta Naik, Satya Eswari Jujjavarapu

Journal of Environmental Chemical Engineering • 2021

Soon Bee Quek, Liang Cheng, Ralf Cord-Ruwisch

Bioresource Technology • 2015

Soon Bee Quek, Liang Cheng, Ralf Cord-Ruwisch

Water Research • 2015

Adib Mahmoodi Nasrabadi, Mahdi Moghimi

International Journal of Hydrogen Energy • 2022