Jakub Dziegielowski, Michele Mascia, Benjamin Metcalfe et al.

Sustainable Energy Technologies and Assessments • 2023

The desire for a net-zero carbon future is a key driver for innovation in renewable energy. Amongst several emerging solutions, soil microbial fuel cells (SMFCs) pose an interesting addition as a low-cost, carbon–neutral technology. A full understanding on the electro-generative processes in SMFCs has, however, yet to be achieved, hindering the technology’s translation into practical applications. In this study, an in-depth investigation into the evolution of the output voltage generated by membrane-less, flat-plate SMFCs that accounts for the contribution of both the anode and cathode potential is provided for the first time, along with a study of the influence that organic matter content and porosity in soil has on voltage dynamics. Four stages in voltage evolution over time were observed, which depended on soil properties. The content of organic matter had the greatest effect, leading to an output voltage nearly-three times higher, when it increased from 10 % to 50 %. In this case, the anode potential reached a value of −450 mV, which prompted an exponential increase in the cathode potential and led to a power density of 68 mWm−2. The experimental findings were used to develop a novel computational model that, by predicting the electrochemical behaviour of the SMFC in different soils, becomes a powerful guide for operating strategies that can markedly enhance electricity generation. Consequently, this study sets the foundation for effective system optimisation and real applications.

Jiuhui Qu, J. Paul Chen

Frontiers of Environmental Science & Engineering • 2024

Abstract The mission of “Establishment of Zero-Pollution Earth” defined by United Nations Environment Programme aims at creation of a clean, safe and prosperous home for all human beings. It is of rational choice from each individual to protect our environment and demonstrates our great ambition to achieve our goals. The key message given in this article is that, zero pollution does not mean no discharge of pollutants and instead it can be achievable through optimizing and controlling a sound balance between pollutants discharge and capacities of decontamination through treatment and natural environmental accumulation, which can be termed as “Principle of Equilibrium” between pollution and decontamination. Based on this principle, we propose and illustrate several key factors and synergistic pathways toward a pollution-free planet: quantitative determination on purification and wastewater; source control through green measures; minimization of negative side-effects; precise management through digitalized systems; and keeping sound balance between pollutants and natural purification. It should be noted that we would face a series of difficulties and challenges in moving forward to “Zero-Pollution Earth”. We should further develop theories, principles and tools to achieve the balance between quantity of pollutants and decontamination capacities. Environmentalists should work together to break through the bottleneck limited by “Principle of equilibrium” to establish new environmental remediation systems leading to “Zero-Pollution Earth”.

Takaya Ogawa, Mizutomo Takeuchi, Yuya Kajikawa

Sustainability • 2018

Fuel cells have been attracting significant attention recently as highly efficient and eco-friendly energy generators. Here, we have comprehensively reviewed all types of fuel cells using computational analysis based on a citation network that detects emerging technologies objectively and provides interdisciplinary data to compare trends. This comparison shows that the technologies of solid oxide fuel cells (SOFCs) and electrolytes in polymer electrolyte fuel cells (PEFCs) are at the mature stage, whereas those of biofuel cells (BFCs) and catalysts in PEFCs are currently garnering attention. It does not mean, however, that the challenges of SOFCs and PEFC electrolytes have been overcome. SOFCs need to be operated at lower temperatures, approximately 500 °C. Electrolytes in PEFCs still suffer from a severe decrease in proton conductivity at low relative humidity and from their high cost. Catalysts in PEFCs are becoming attractive as means to reduce the platinum catalyst cost. The emerging technologies in PEFC catalysts are mainly heteroatom-doped graphene/carbon nanotubes for metal-free catalysts and supports for iron- or cobalt-based catalysts. BFCs have also received attention for wastewater treatment and as miniaturized energy sources. Of particular interest in BFCs are membrane reactors in microbial fuel cells and membrane-less enzymatic biofuel cells.

Hao Wu, Yiyu Chen, Wenlong Xu et al.

Nature Communications • 2023

Miniaturized rotors based on Marangoni effect have attracted great attentions due to their promising applications in propulsion and power generation. Despite intensive studies, the development of Marangoni rotors with high rotation output and fuel economy remains challenging. To address this challenge, we introduce an asymmetric porosity strategy to fabricate Marangoni rotor composed of thermoresponsive hydrogel and low surface tension anesthetic metabolite. Combining enhanced Marangoni propulsion of asymmetric porosity with drag reduction of well-designed profile, our rotor precedes previous studies in rotation output (~15 times) and fuel economy (~34% higher). Utilizing thermoresponsive hydrogel, the rotor realizes rapid refueling within 33 s. Moreover, iron-powder dopant further imparts the rotors with individual-specific locomotion in group under magnetic stimuli. Significantly, diverse functionalities including kinetic energy transmission, mini-generator and environmental remediation are demonstrated, which open new perspectives for designing miniaturized rotating machineries and inspire researchers in robotics, energy, and environment.

Ferd Pilz, Patrycja Kielb

BBA Advances • 2023

In this article, we cross-examine three well-established electrochemical approaches, namely cyclic voltammetry (CV), cyclic square-wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) to dissect the electron transfer (ET) rate of electrostatically immobilized cytochrome c on Ag electrodes. A detailed analysis supported by simulations of redox transition provided three distinct values for the heterogeneous electron transfer (HET) rate constant of cyt c interfaced on COOH-terminated C 10 -long alkanethiol, i.e., k HET = 47.8 (±2,91) s -1 in CV, k HET = 64.8 (±1,27) s -1 in SWV, and k HET = 26.5 s -1 in EIS. We discuss the obtained discrepancies obtained from electrochemical methods and compare them with the data from spectro-electrochemical experiments. A comprehensive selection list is created from which the most applicable approach can be chosen for studying proteins of interest. CV is most applicable to study the interfaced proteins exhibiting k HET of ca. 0.5 - 70 s -1 , SWV is suitable for a broader range of k HET of 5 - 120 s -1 and EIS for k HET of 0.5 to 5 s -1 if alkanethiols are used as immobilization strategy.

Richa Mishra, Bidhan Pramanick, Tapas K. Maiti et al.

Microsystems & Nanoengineering • 2018

Because carbon is the basic element of all life forms and has been successfully applied as a material for medical applications, it is desirable to investigate carbon for drug delivery applications, as well. In this work, we report the fabrication of a hollow carbon microneedle array with flow channels using a conventional carbon-microelectromechanical system (C-MEMS) process. This process utilizes the scalable and irreversible step of pyrolysis, where prepatterned SU-8 microneedles (precursor) are converted to glassy carbon structures in an inert atmosphere at high temperature (900 °C) while retaining their original shape upon shrinkage. Once converted to glassy carbon, the microneedles inherit the unique properties of hardness, biocompatibility, and thermal and chemical resistance associated with this material. A comparative study of hardness and Young's modulus for carbon microneedles and SU-8 microneedles was performed to evaluate the increased strength of the microneedles induced by the C-MEMS process steps. Structural shrinkage of the carbon microneedles upon pyrolysis was observed and estimated. Material characterizations including energy-dispersive X-ray spectroscopy (EDX) and Raman spectroscopy were carried out to estimate the atomic percentage of carbon in the microneedle structure and its crystalline nature, respectively. Our investigations confirm that the microneedles are glassy in nature. Compression and bending tests were also performed to determine the maximum forces that the carbon microneedles can withstand, and it was found that these forces were approximately two orders of magnitude higher than the resistive forces presented by skin. A microneedle array was inserted into mouse skin multiple times and was successfully removed without the breakage of any microneedles.

Pilar C. Portela, Catharine Shipps, Cong Shen et al.

Nature Communications • 2024

Extracellular electron transfer (EET) via microbial nanowires drives globally-important environmental processes and biotechnological applications for bioenergy, bioremediation, and bioelectronics. Due to highly-redundant and complex EET pathways, it is unclear how microbes wire electrons rapidly (>10 6 s -1 ) from the inner-membrane through outer-surface nanowires directly to an external environment despite a crowded periplasm and slow (<10 5 s -1 ) electron diffusion among periplasmic cytochromes. Here, we show that Geobacter sulfurreducens periplasmic cytochromes PpcABCDE inject electrons directly into OmcS nanowires by binding transiently with differing efficiencies, with the least-abundant cytochrome (PpcC) showing the highest efficiency. Remarkably, this defined nanowire-charging pathway is evolutionarily conserved in phylogenetically-diverse bacteria capable of EET. OmcS heme reduction potentials are within 200 mV of each other, with a midpoint 82 mV-higher than reported previously. This could explain efficient EET over micrometres at ultrafast (<200 fs) rates with negligible energy loss. Engineering this minimal nanowire-charging pathway may yield microbial chassis with improved performance.

Pedro N. Carvalho, Carlos Alberto Arias, Hans Brix

Water • 2017

Constructed wetlands (CWs) are currently regarded as established eco-technologies to treat water pollution. Although considered near-natural systems, they are totally engineered solutions for which research has been actively developed over the past decades. This paper provides a brief meta-analysis on the latest scientific publications in the field and an overview of the special issue focused on the new developments in the use of CWs for water treatment. The selected papers cover a wide range of relevant developments in the field, including the use of different CW system designs, the capacity to treat different types of pollutants, and studies aiming at getting a better understanding of the treatment processes in CWs.

Na Chen, Na Du, Ruichen Shen et al.

Nature Communications • 2023

Microbial communication can drive coordinated functions through sensing, analyzing and processing signal information, playing critical roles in biomanufacturing and life evolution. However, it is still a great challenge to develop effective methods to construct a microbial communication system with coordinated behaviors. Here, we report an electron transfer triggered redox communication network consisting of three building blocks including signal router, optical verifier and bio-actuator for microbial metabolism regulation and coordination. In the redox communication network, the Fe 3+ /Fe 2+ redox signal can be dynamically and reversibly transduced, channeling electrons directly and specifically into bio-actuator cells through iron oxidation pathway. The redox communication network drives gene expression of electron transfer proteins and simultaneously facilitates the critical reducing power regeneration in the bio-actuator, thus enabling regulation of microbial metabolism. In this way, the redox communication system efficiently promotes the biomanufacturing yield and CO 2 fixation rate of bio-actuator. Furthermore, the results demonstrate that this redox communication strategy is applicable both in co-culture and microbial consortia. The proposed electron transfer triggered redox communication strategy in this work could provide an approach for reducing power regeneration and metabolic optimization and could offer insights into improving biomanufacturing efficiency.

Zhe Wang, Guangjin Wang, Wenyao Li et al.

Applied Surface Science • 2021

Carolina Cruz Viggi, Bruna Matturro, Emanuela Frascadore et al.

Water Research • 2017

Caterina Brandoni, B. Bošnjaković

Journal of Cleaner Production • 2016

Lunjia Zhang, Meng Gao, Ronghang Wang et al.

Sensors • 2019

Nowadays, with the development of wearable devices, stretchable pressure sensors have been widely adopted in all kinds of areas. Most of the sensors aim to detect small pressure, such as fingertip tactile sensing, but only a few are focused on high-pressure sensing, such as foot pressure sensing during men's walking. In this work, a liquid metal-based stretchable sensor for large-pressure measurement is investigated. This sensor is fully stretchable because it is made of soft materials. However, when the soft sensor is subjected to high pressure, the liquid metal easily leaks from microchannels because it maintains the liquid state at room temperature. We therefore propose to fabricate liquid metal-based leakage-free electrodes to handle the liquid-metal leak. Parametric studies are conducted to compare this sensor with liquid-metal-only electrodes and leakage-free electrodes. The leakage-free electrodes increase the measurement ranges from 0.18, 0.18, and 0.15 MPa to 0.44 MPa, with higher linearity and precision. The improvement in the liquid-metal electrode enables the sensors to work stably within 0.44 MPa pressure and 20% strain. In addition, we integrate two capacitors, namely, a working capacitor and a reference capacitor, into one sensor to reduce the influence of parasitic capacitance brought about by external interference. This stretchable capacitive sensor capable of working under a wide range of pressure with good repeatability, sensitivity, and linearity, exhibits great potential use for wearable electronics. Finally, the method for fabricating leakage-free electrodes shows great value for hyperelastic electronics manufacturing and micromachine technology.

Azamat Suleymanov, И. М. Габбасова, Mikhail Komissarov et al.

Agriculture • 2023

The problem of salinization/spreading of saline soils is becoming more urgent in many regions of the world, especially in context of climate change. The monitoring of salt-affected soils’ properties is a necessary procedure in land management and irrigation planning and is aimed to obtain high crop harvest and reduce degradation processes. In this work, a machine learning method was applied for modeling of the spatial distribution of topsoil (0–20 cm) properties—in particular: soil organic carbon (SOC), pH, and salt content (dry residue). A random forest (RF) machine learning approach was used in combination with environmental variables to predict soil properties in a semi-arid area (Trans-Ural steppe zone). Soil, salinity, and texture maps; topography attributes; and remote sensing data (RSD) were used as predictors. The coefficient of determination (R2) and the root mean square error (RMSE) were used to estimate the performance of the RF model. The cross-validation result showed that the RF model achieved an R2 of 0.59 and an RMSE of 0.68 for SOM; 0.36 and 0.65, respectively, for soil pH; and 0.78 and 1.21, respectively for dry residue prediction. The SOC content ranged from 0.8 to 2.8%, with an average value of 1.9%; soil pH ranged from 5.9 to 8.4, with an average of 7.2; dry residue varied greatly from 0.04 to 16.8%, with an average value of 1.3%. A variable importance analysis indicated that remote sensing variables (salinity indices and NDVI) were dominant in the spatial prediction of soil parameters. The importance of RSD for evaluating saline soils and their properties is explained by their absorption characteristics/reflectivity in the visible and near-infrared spectra. Solonchak soils are distinguished by a salt crust on the land surface and, as a result, reduced SOC contents and vegetation biomass. However, the change in saline and non-saline soils over a short distance with mosaic structure of soil cover requires high-resolution RSD or aerial images obtained from unmanned aerial vehicle/drones for successful digital mapping of soil parameters. The presented results provide an effective method to estimate soil properties in saline landscapes for further land management/reclamation planning of degraded soils in arid and semi-arid regions.

Yu Sugimoto, Yuki Kitazumi, Osamu Shirai et al.

Electrochemistry • 2017

Direct electron transfer (DET)-type bioelectrocatalytic waves of bilirubin oxidase (BOD)-catalyzed O2 reduction and [NiFe] hydrogenase (H2ase)-catalyzed H2 oxidation are very small and un-detectable using glassy carbon (GC) electrodes, respectively; however, clear catalytic waves are observed when the enzymes are adsorbed on Ketjen black-modified GC (KB-GC) electrodes, in which KB provides mesopores for DET-type bioelectocatalysis. To explain the phenomena, we focus on the curvature effect of mesoporous structures on long range electron transfer kinetics and simulate steady-state voltammograms catalyzed by model redox enzymes adsorbed with a random orientation on planar and mesoporous electrodes based on a three-dimensional model. In the simulation, we assume a spherical enzyme with a radius of r, an active site located at a certain distance from the center of the enzyme, and a spherical pore with a radius of Rp in mesoporous electrodes in which the enzyme is trapped and adsorbed. The simulation reveals that mesoporous electrodes provide platforms suitable for DET-type bioelectrocatalysis of enzymes when Rp becomes close to r. Such curvature effects of mesoporous electrodes become especially notable for larger sized enzymes. Furthermore, the simulation reproduces the experimental data of BOD- and H2ase-catalyzed DET-type waves by considering the crystal structures of the enzymes. This work will open a route to improve the kinetic performance of the DET-type bioelectrocatalysis that has become very important in its practical application to a variety of bioelectrochemical devices.

M.J. Salar-García, Alberto de Ramón-Fernández, V.M. Ortiz-Martínez et al.

Biochemical Engineering Journal • 2019

Microbial fuel cells (MFCs) are an environment-friendly technology, which addresses two of the most important environmental issues worldwide: fossil fuel depletion and water scarcity. Modelling is a useful tool that allows us to understand the behaviour of MFCs and predict their performance, yet the number of MFC models that could accurately inform a scale-up process, is low. In this work, a three-factor three-level Box-Behnken design is used to evaluate the influence of different operating parameters on the performance of air-breathing ceramic-based MFCs fed with human urine. The statistical analysis of the 45 tests run shows that both anode area and external resistance have more influence on the power output than membrane thickness, in the range studied. The theoretical optimal conditions were found at a membrane thickness of 1.55 mm, an external resistance of 895.59 Ω and an anode area of 165.72 cm 2 , corresponding to a maximum absolute power generation of 467.63 μW. The accuracy of the second order model obtained is 88.6%. Thus, the three-factor three-level Box-Behnken-based model designed is an effective tool which provides key information for the optimisation of the energy harvesting from MFC technology and saves time in terms of experimental work.

Fauziah Marpani, Zsuzsa Sárossy, Manuel Pinelo et al.

Biotechnology and Bioengineering • 2017

Enzymatic reduction of carbon dioxide (CO 2 ) to methanol (CH 3 OH) can be accomplished using a designed set-up of three oxidoreductases utilizing reduced pyridine nucleotide (NADH) as cofactor for the reducing equivalents electron supply. For this enzyme system to function efficiently a balanced regeneration of the reducing equivalents during reaction is required. Herein, we report the optimization of the enzymatic conversion of formaldehyde (CHOH) to CH 3 OH by alcohol dehydrogenase, the final step of the enzymatic redox reaction of CO 2 to CH 3 OH, with kinetically synchronous enzymatic cofactor regeneration using either glucose dehydrogenase (System I) or xylose dehydrogenase (System II). A mathematical model of the enzyme kinetics was employed to identify the best reaction set-up for attaining optimal cofactor recycling rate and enzyme utilization efficiency. Targeted process optimization experiments were conducted to verify the kinetically modeled results. Repetitive reaction cycles were shown to enhance the yield of CH 3 OH, increase the total turnover number (TTN) and the biocatalytic productivity rate (BPR) value for both system I and II whilst minimizing the exposure of the enzymes to high concentrations of CHOH. System II was found to be superior to System I with a yield of 8 mM CH 3 OH, a TTN of 160 and BPR of 24 μmol CH 3 OH/U · h during 6 hr of reaction. The study demonstrates that an optimal reaction set-up could be designed from rational kinetics modeling to maximize the yield of CH 3 OH, whilst simultaneously optimizing cofactor recycling and enzyme utilization efficiency.

Charlène Beaufils, Hiu-Mun Man, Anne de Poulpiquet et al.

Catalysts • 2021

Bioelectrocatalysis using redox enzymes appears as a sustainable way for biosensing, electricity production, or biosynthesis of fine products. Despite advances in the knowledge of parameters that drive the efficiency of enzymatic electrocatalysis, the weak stability of bioelectrodes prevents large scale development of bioelectrocatalysis. In this review, starting from the understanding of the parameters that drive protein instability, we will discuss the main strategies available to improve all enzyme stability, including use of chemicals, protein engineering and immobilization. Considering in a second step the additional requirements for use of redox enzymes, we will evaluate how far these general strategies can be applied to bioelectrocatalysis.

Nabin Aryal, Torben Kvist

ChemEngineering • 2018

The Danish government has set an ambitious target to achieve 100% fossil independence across all energy sectors, which demands optimum utilization of renewable energy sources, such as wind and biogas, by 2050. Biogas production has increased, and the upgrading of biogas offers a broad range of applications, such as transportation, and gas grid injection for downstream utilization. The biogas has to meet natural gas quality prior to injection into the gas grid system. The investment costs of the gas grid, upgrading cost, and gas compression costs are the major challenges for integrating the biogas into the existing gas infrastructure. In this investigation, the Wobbe index (WI) for raw biogas and upgraded biogas was measured to evaluate the scenario for biogas injection into the gas grid system. It was found that raw biogas has to improve its WI from 28.3 MJ/m3(n) to a minimum of 50.76 MJ/m3(n) via upgrading, and compressed to 40 bar system, to supply the gas grid system for trading. Then, yearly gas consumption by larger gas consumers was studied to evaluate the alternative approach of biogas utilization to save upgrading and compression costs for gas grid injection.

A. Miguel, Gábor Cśanyi, Tomi Laurila et al.

Physical review. B./Physical review. B • 2020

Amorphous carbon (a-C) materials have diverse interesting and useful properties, but the understanding of their atomic-scale structures is still incomplete. Here, we report on extensive atomistic simulations of the deposition and growth of a-C films, describing interatomic interactions using a machine learning (ML) based Gaussian approximation potential model. We expand widely on our initial work [M. A. Caro et al., Phys. Rev. Lett. 120, 166101 (2018)] by now considering a broad range of incident ion energies, thus modeling samples that span the entire range from low-density ($s{p}^{2}$-rich) to high-density ($s{p}^{3}$-rich, ``diamondlike'') amorphous forms of carbon. Two different mechanisms are observed in these simulations, depending on the impact energy: low-energy impacts induce $sp$- and $s{p}^{2}$-dominated growth directly around the impact site, whereas high-energy impacts induce peening. Furthermore, we propose and apply a scheme for computing the anisotropic elastic properties of the a-C films. Our work provides fundamental insight into this intriguing class of disordered solids, as well as a conceptual and methodological blueprint for simulating the atomic-scale deposition of other materials with ML driven molecular dynamics.

Ajinkya Nene, Sorour Sadeghzade, Stefano Viaroli et al.

Environmental Sciences Europe • 2025

The degradation of mismanaged plastic waste in the environment results in the formation of microplastics (MPs) and nanoplastics (NPs), which pose significant risks to ecosystems and human health. These particles are pervasive, detected even in remote regions, and can enter the food chain, accumulating in organisms and causing harm depending on factors such as particle load, exposure dose, and the presence of co-contaminants. Detecting and analyzing NMPs present unique challenges, particularly as particle size decreases, making them increasingly difficult to identify. Moreover, the absence of standardized protocols for their detection and analysis further hinders comprehensive assessments of their environmental and biological impacts. This review provides a detailed overview of the latest advancements in technologies for sampling, separation, measurement, and quantification of NMPs. It highlights promising approaches, supported by practical examples from recent studies, while critically addressing persistent challenges in sampling, characterization, and analysis. This work examines cutting-edge developments in nanotechnology-based detection, integrated spectro-microscopic techniques, and AI-driven classification algorithms, offering solutions to bridge gaps in NMP research. By exploring state-of-the-art methodologies and presenting future perspectives, this review provides valuable insights for improving detection capabilities at the micro- and nanoscale, enabling more effective analysis across diverse environmental contexts.

Shenghua Yin, Leiming Wang, Eugie Kabwe et al.

Minerals • 2018

The commercial application of copper bioleaching, an environmentally-friendly approach for low-grade and secondary mineral resources recycling, has increased worldwide since the 2000s. As the world’s second-largest economic entity and the largest developing country, China has the largest demand for metal resources, significantly advancing the theory and industrial technology of copper bioleaching. This paper reviews the exploration and application of copper bioleaching in China. Two typical bioleaching applications and technological processes, bioheap leaching at the Zijinshan Copper Mine and bioheap leaching at the Dexing Copper Mine, are introduced. The considerable research completed by researchers is summarized, especially focusing on the isolation and identification of leaching bacteria, the bioleaching mechanism and interface reactions, multistage percolation behavior, bioleaching system reconstruction, the multiphysics coupled model, and enhanced copper bioleaching from waste printed circuit boards (WPCBs). Based on this investigation in China, key trends and prospects in copper bioleaching—such as efficiency improvement, environmental protection, and improved technology applications—are proposed.

Авни Бериша

Open Chemistry • 2019

Abstract The mechanism of the adsorption and grafting of diazonium cations onto the surface of graphyne and graphdiyne was investigated using Density Functional Theory (DFT). The adsorption energy (both in vacuum and water as solvent) of the phenyl diazonium cation was evaluated at three different positions of the graphyne and graphdiyne surface. Moreover, the lowest energy adsorption sites were used to calculate and plot Non-covalent Interactions (NCI). The Bond Dissociation Energy (BDE) results (up to 66 kcal/mol) for the scission of the phenyl group support the remarkable stability of the grafted layer. As both of these materials are non-dispersible in aqueous solution, in this work through the use of Molecular Mechanics (MM) and Molecular Dynamics (MD) we explored also the effect of the grafted substituted aryl groups derived from aryldiazonium salts onto the solvation properties of these materials.

Pedro N. Carvalho, David C. Finger, Fabio Masi et al.

Journal of Cleaner Production • 2022

An increasing world population is projected to increase water, energy and food requirements, three vital resources for humankind. Projected climate change impacts will aggravate water availability, as well as flood risks, especially in urban areas. Nature-based solutions (NBS) have been identified as key concepts to defuse the expected tensions within the Water-Energy-Food (W-E-F) nexus due to their multiple benefits. In this paper, the authors outlined the theories and concepts, analyzed real-life case studies, and discussed the potential of NBS to address the future W-E-F nexus. For this purpose, we performed a systematic literature review on the theories of NBS that address the W-E-F nexus, and we summarized 19 representative real-life case studies to identify the current knowledge gaps and challenges. The quantitative and qualitative data was used to differentiate and discuss the direct and indirect potential benefits of NBS to the W-E-F nexus. The study further expanded on the challenges for the implementation of NBS and highlighted the growing possibilities in the context of circularity and the implementation of NBS in urban planning. It was concluded that the potential impacts of NBS on the W-E-F nexus have been identified, but the quantitative effects have not been analyzed in-depth. Moreover, indicators are mostly single-purpose and not multipurpose, as required to fully characterize the W-E-F nexus and circularity holistically. Overall, there is a need to adopt systemic thinking and promote the multipurpose design of NBS.

Lei Zhao, Jian Li, Francine Battaglia et al.

Chemical Engineering Journal • 2016

Sylwia Baluta, Francesca Meloni, Kinga Halicka et al.

RSC Advances • 2022

The main goal of the presented study was to design a biosensor-based system for epinephrine (EP) detection using a poly-thiophene derivative and tyrosinase as a biorecognition element. We compared two different electroanalytical techniques to select the most prominent technique for analyzing the neurotransmitter. The prepared biosensor system exhibited good parameters; the differential pulse (DPV) technique presented a wide linear range (1-20 μM and 30-200 μM), with a low detection limit (0.18 nM and 1.03 nM). In the case of chronoamperometry (CA), a high signal-to-noise ratio and lower reproducibility were observed, causing a less broad linear range (10-200 μM) and a higher detection limit (125 nM). Therefore, the DPV technique was used for the calculation of sensitivity (0.0011 μA mM -1 cm -2 ), stability (49 days), and total surface coverage (4.18 × 10 -12 mol cm -2 ). The biosensor also showed very high selectivity in the presence of common interfering species ( i.e. ascorbic acid, uric acid, norepinephrine, dopamine) and was successfully applied for EP determination in a pharmaceutical sample.

Taiki Adachi, Yuki Kitazumi, Osamu Shirai et al.

Catalysts • 2020

Direct electron transfer (DET)-type bioelectrocatalysis, which couples the electrode reactions and catalytic functions of redox enzymes without any redox mediator, is one of the most intriguing subjects that has been studied over the past few decades in the field of bioelectrochemistry. In order to realize the DET-type bioelectrocatalysis and improve the performance, nanostructures of the electrode surface have to be carefully tuned for each enzyme. In addition, enzymes can also be tuned by the protein engineering approach for the DET-type reaction. This review summarizes the recent progresses in this field of the research while considering the importance of nanostructure of electrodes as well as redox enzymes. This review also describes the basic concepts and theoretical aspects of DET-type bioelectrocatalysis, the significance of nanostructures as scaffolds for DET-type reactions, protein engineering approaches for DET-type reactions, and concepts and facts of bidirectional DET-type reactions from a cross-disciplinary viewpoint.

Miriam Edel, Gunnar Sturm, Katrin Richter et al.

Biotechnology for Biofuels • 2021

This study describes a new quorum-sensing mechanism in S. oneidensis. Biofilm formation of S. oneidensis is induced by low concentrations of riboflavin resulting in an upregulation of the ornithine-decarboxylase speC. The results can be applied for the development of strains catalyzing increased current densities in bioelectrochemical systems.

Hubert Müller, Julian Bosch, Christian Griebler et al.

The ISME Journal • 2016

The biodegradation of organic pollutants in aquifers is often restricted to the fringes of contaminant plumes where steep countergradients of electron donors and acceptors are separated by limited dispersive mixing. However, long-distance electron transfer (LDET) by filamentous 'cable bacteria' has recently been discovered in marine sediments to couple spatially separated redox half reactions over centimeter scales. Here we provide primary evidence that such sulfur-oxidizing cable bacteria can also be found at oxic-anoxic interfaces in aquifer sediments, where they provide a means for the direct recycling of sulfate by electron transfer over 1-2-cm distance. Sediments were taken from a hydrocarbon-contaminated aquifer, amended with iron sulfide and saturated with water, leaving the sediment surface exposed to air. Steep geochemical gradients developed in the upper 3 cm, showing a spatial separation of oxygen and sulfide by 9 mm together with a pH profile characteristic for sulfur oxidation by LDET. Bacterial filaments, which were highly abundant in the suboxic zone, were identified by sequencing of 16S rRNA genes and fluorescence in situ hybridization (FISH) as cable bacteria belonging to the Desulfobulbaceae. The detection of similar Desulfobulbaceae at the oxic-anoxic interface of fresh sediment cores taken at a contaminated aquifer suggests that LDET may indeed be active at the capillary fringe in situ.

Yangqi Gu, Matthew J. Guberman‐Pfeffer, Vishok Srikanth et al.

Nature Microbiology • 2023

Maria Vomero, Elisa Castagnola, Francesca Ciarpella et al.

Scientific Reports • 2017

We report on the superior electrochemical properties, in-vivo performance and long term stability under electrical stimulation of a new electrode material fabricated from lithographically patterned glassy carbon. For a direct comparison with conventional metal electrodes, similar ultra-flexible, micro-electrocorticography (μ-ECoG) arrays with platinum (Pt) or glassy carbon (GC) electrodes were manufactured. The GC microelectrodes have more than 70% wider electrochemical window and 70% higher CTC (charge transfer capacity) than Pt microelectrodes of similar geometry. Moreover, we demonstrate that the GC microelectrodes can withstand at least 5 million pulses at 0.45 mC/cm 2 charge density with less than 7.5% impedance change, while the Pt microelectrodes delaminated after 1 million pulses. Additionally, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) was selectively electrodeposited on both sets of devices to specifically reduce their impedances for smaller diameters (<60 μm). We observed that PEDOT-PSS adhered significantly better to GC than Pt, and allowed drastic reduction of electrode size while maintaining same amount of delivered current. The electrode arrays biocompatibility was demonstrated through in-vitro cell viability experiments, while acute in vivo characterization was performed in rats and showed that GC microelectrode arrays recorded somatosensory evoked potentials (SEP) with an almost twice SNR (signal-to-noise ratio) when compared to the Pt ones.

Vafa Ahmadi, Nabin Aryal

Linköping electronic conference proceedings • 2025

Bioelectrochemical systems (BESs) have garnered extensive research attention for their biosynthesis and environmental remediation applications. One of the challenges to upscaling BES for carbon dioxide (CO2) methanation is energy-efficient process development. Investigations are ongoing to determine the relationship between the yield of electroactive microorganisms, the key candidates for electrochemical reactions with external electricity input. Consequently, simulating processes, particularly with biocathode for biosynthesis and bioanode for remediation, gives crucial insights for designing efficient BESs. The framework for establishing Nernst-Monod equations for modeling BES, starts from bioanode, where anode respiring bacteria (ARB) oxidize organic carbon compounds to CO2, and generate the proton (H+). In this work, kinetic modeling was applied to calculate the biomass yield of ARBs corresponding to the applied anodic voltage. The generated CO2 and H+ from the anode determined the biomass yield of electroactive methanogens and acetogens on the cathode. Two biofilm models were established for anodic and cathodic biofilm growth in the Aquasim simulation tool. Results showed that the concentration of organic carbon compound (acetate) available for ARB, had a significant impact on the biofilm thickness and biomass concentration on the biofilm, especially at +0.3 V. The optimum anode voltage which released the highest CO2 and H+, was +0.3 V. The anodic and cathodic biofilm thickness reached 3 mm and 55 µm, respectively, at +0.3 V and 10 g.L-1 acetate input to the anode chamber. Moreover, methanogens surpassed acetogens on the biocathode for CO2 reduction to methane rather than acetate. In addition, acetate consumption rate by ARB at anode was remarkably faster than acetate production at cathode.

Jiannan Li, Ye Qiu, Yan Tian et al.

ACS ES&T Engineering • 2024

As an emerging technology, ecological floating beds coupled with microbial electrochemical systems (ECOFB-MESs) offer the road for synchronous remediation of actual polluted surface water and sediment along with the recovery of bioenergy from pollutants. However, the selection and arrangement of large-scale anodes to achieve optimal pollutant removal efficiency and system output performance remain unexplored. In this study, various types of anode units (2D anodes: carbon cloth and 3D anodes: carbon felt) with different configurations (integral and independent connection) were employed in the remediation of actual polluted surface water to investigate their impact on system performance. The results indicate that 2D integral anodes exhibited superior sediment organic pollutant removal rates (integral: 73.6 ± 1.1%, independent connection: 71.2 ± 0.8%) and bioelectrochemical performance (integral: 2.881 ± 0.016 mW/m2, independent connection: 2.387 ± 0.008 mW/m2) compared to independently connected anodes of the same projected areas. Model simulations using COMSOL software revealed that the connection of multiple independent anodes led to system performance degradation due to increased potential drop during electron transport in the anode. Furthermore, the introduction of pores in 3D anodes did not contribute to an increased potential drop. However, it resulted in improved pollutant removal rates and system output performance by 3.1 and 11.2%, respectively. Model simulations suggested that integral anodes should be employed in practical applications to mitigate potential drops caused by connections and ensure optimal system performance. This research provides valuable insights and strategies for the large-scale construction of anodes in ECOFB-MES.

Sheng‐Song Yu, Lei Cheng, Jie‐Jie Chen et al.

ACS Applied Materials & Interfaces • 2018

A bioelectrochemical system (BES) allows direct electricity production from wastes, but its low-power density, which is mainly associated with its poor anodic performance, limits its practical applications. Here, the anodic performance of a BES can be significantly improved by electrodepositing vitamin B 2 (VB 2 ) onto a graphene [reduced graphene oxide (rGO)]-modified glassy carbon electrode (VB 2 /rGO/GC) with Geobacter sulfurreducens as the model microorganisms. The VB 2 /rGO/GC electrode results in 200% higher electrochemical activity than a bare GC anode. Additionally, in microbial electrolysis cells, the current density of this composite electrode peaks at ∼210 μA cm -2 after 118 h and is maintained for 113 h. An electrochemical analysis coupled with molecular simulations reveals that using VB 2 as a linker between the electrochemically active protein of this model strain and the rGO surface accelerates the electron transfer, which further improves the bioelectricity generation and favors the long-term stability of the BES. The VB 2 bound with a flexible ribityl group as the organic molecular bridge efficiently mediates energy conversion in microbial metabolism and artificial electronics. This work provides a straightforward and effective route to significantly enhance the bioenergy generation in a BES.

Ziming Yang, Aidong Yang

Biochemical Engineering Journal • 2020

Qingyun Ping, Ibrahim M. Abu-Reesh, Zhen He

The Science of The Total Environment • 2016

Mohamad Fazli, Saleh Moradi‐Alavian, Amir Kazempour et al.

Applied Organometallic Chemistry • 2025

ABSTRACT This study explores the electrocatalytic performance of a new composite material, ZIF‐8@PPy/3D‐Ni, for hydrogen evolution reaction (HER) in water splitting. We synthesized ZIF‐8 using a straightforward electrodeposition method and characterized it with X‐ray diffraction (XRD), Fourier‐transform infrared (FT‐IR) spectroscopy, and Raman spectroscopy. The ZIF‐8@PPy composite was created by electrodepositing polypyrrole (PPy) on a 3D‐Ni substrate, optimizing the PPy concentration, electrodeposition time, and electrodeposition potential. Electrochemical tests showed that the ZIF‐8@PPy/3D‐Ni electrode had a low overpotential of 173 mV at 100 mA cm −2 . The Tafel slope for the composite was 64.3 mV dec −1 , indicating improved kinetics compared to PPy alone (85.5 mV dec −1 ). Adding ZIF‐8 improved the catalytic activity due to its high‐surface area and nitrogen groups that helped proton absorption. The electrode's stability was confirmed by chronopotentiometry, showing promise for practical use in sustainable hydrogen production. Overall, this work demonstrates the effectiveness of ZIF‐8@PPy as an electrocatalyst for HER, contributing to future renewable energy technologies.

Ismael Carlos Braga Alves, José Ribamar Nascimento dos Santos, Edmar Pereira Marques et al.

Analytical Sciences • 2023

Semra Yaşar Çırak, Dilara Öztürk, Abdurrahman Akyol

Water Air & Soil Pollution • 2025

Abstract The process of electrooxidation of the active substances Paracetamol (PCT), benzoquinone (BQ) and hydroquinone (HQ) was studied using a set of different dimensionally stable anode (DSA) and Boron doped diamond (BDD) electrodes. Comparison of the efficiency of electrocatalytic anodes was assessed using percent total organic carbon (%TOC) removal and PCT amount removal values. The removal of %TOC in synthetically prepared waters for the BDD anode reached 96%, for DSA electrodes Ti/PbO 2 -IrO 2 -RuO 2 57%, Ti/IrO 2 -RuO 2 -TiO 2 35%, Ti/IrO 2 -RuO 2 -SnO 2 31%, Ti/RuO 2 -SnO 2 30% and Pt 24%. BDD effectively degrades PCT and almost completely mineralizes BQ and HQ. A DSA-Ti/PbO 2 -IrO 2 -RuO 2 electrode and a BDD electrode were used in the electrooxidation process of real industrial wastewater containing PCT. The BDD electrode had a TOC removal efficiency of 58%, while the DSA-Ti/PbO 2 -IrO 2 -RuO 2 electrode achieved 52%. Despite similar values ​​of PCT removal by both electrodes, the Ti/PbO 2 -IrO 2 -RuO 2 anode showed low mineralization of organic matter. The originality of this paper lies in the study of the electrooxidation of real PCT wastewater and the use of a Ti/PbO 2 -IrO 2 -RuO 2 electrode. Graphical Abstract

M.A.M. Cartaxo, Joanna Fernandes, Marcus Paulo De Moraes Gomes et al.

Portugaliae electrochimica acta • 2022

Due to its highest gravimetric energy density, H2 has been regarded as the preferred cleanenergy carrier, with potentially environmentally-friendly production through the solarassisted WS. Since human activities generate enormous amounts of WW, H2 production from this new resource has gained attention as an emergent technology. This paper addresses the most relevant and current aspects of H2 production from WWEL, and electricity generation from RES. In this sense, the state of art of H2 production, especially from WS, is presented here, as well as the main approaches to electricity generation from RES, with the greatest potential for viability. A new approach on this matter, which is part of the work that is being developed by the authors of this study, was also herein presented.