Carbon Felt Research Articles

Carbon Felt/Nickel Oxide/Polyaniline Nanocomposite as a Bifunctional Anode for Simultaneous Power Generation and Energy Storage in a Dual-Chamber MFC

Microbial fuel cell (MFC) technology has become a novel and attractive method for generating renewable energy during wastewater treatment. In this study, researchers combined carbon felt (CF), metal oxide (NiO), and polyaniline (PANI) to prepare CF/NiO/PANI multilayer capacitive bioelectrodes. The MFC equipped with a CF/NiO/PANI bioanode has a peak power density of 1988.31 ± 50.96 mW/m2, which is 3.8 times higher than that of the MFC with a bare CF electrode, having a peak power density of 518.29 ± 27.07 mW/m2. Charge–discharge cycle tests show that the storage charge capacity of the CF/NiO/PANI bioanode is 3304.64 C/m2, which is 10.5 times greater than that of the bare CF anode. The electrochemical, morphological, and chemical properties of the prepared anodes are characterized using techniques such as SEM, EDS, FTIR, XPS, and XRD. Notably, high-throughput sequencing reveals that electrogenic bacteria account for 79.2% of the total microbial population on the CF/NiO/PANI multilayer capacitive bioelectrode. The synergistic effects of the composite materials result in the formation of a richer biofilm on the electrode surface, providing more active sites and enhancing capacitive characteristics. This innovative approach significantly improves the output power and peak current of MFCs, while also endowing the electrode with dual functions of simultaneous power generation and energy storage.

Encapsulated High-Salt but Corrosion-Resistant Hygroscopic Medium for Long-Term Passive Solar Cell Cooling.

Cooling the solar panel with hygroscopic materials offers a potential solution to mitigate its thermal damage and photovoltaic efficiency reduction. However, the practical application of this approach is significantly hindered by the limited water storage capacity and the back electrode corrosion. In this study, it is demonstrated that encapsulating LiCl-loaded carbon felt in a superhydrophobic polytetrafluoroethylene membrane effectively preserves its high absorptivity while preventing the conventional corrosion issue. This approach ensures sustainable and long-term passive cooling of solar cells. The high-salt but corrosion-resistant (HSCR) material has extremely high water adsorption and storage capacities, which is characterized by the ability to absorb more than 5 times its weight of water within 8 h of incubation at 25°C and 90% relative humidity (RH). Under 1 sun illumination, incorporating HSCR reduces the solar panel temperature by 17.8°C while increasing the photovoltaic efficiency by 10.7%. More importantly, the salts encapsulated within the membrane remain leak-proof and the cooling performance can be effectively regenerated after multiple cycles. This work provides a promising solution for sustainable and passive solar panel cooling.

Painted Electrode with Activated Coconut Carbon for Microbial Fuel Cell

A microbial fuel cell (MFC) is a bio-electrochemical system that utilizes electroactive microorganisms to generate electricity. These microorganisms, which convert the energy stored in substrates such as wastewater into electricity, grow on the anode. To ensure biocompatibility, anodes are typically made from carbon-based materials. Therefore, a carbon-based material (by-product of coconut processing) was selected for testing in this study. The anode was prepared by bonding activated coconut carbon with carbon paint on a glass electrode. The aim of this study was to analyze the feasibility of using an electrode prepared in this manner as a surface layer on the anode of an MFC. The performance of an electrode coated only with carbon paint was also evaluated. These two electrodes were compared with a carbon felt electrode, which is commonly used as an anode material in MFCs. In this research, the MFC was fed with a by-product of yeast production, namely a molasses decoction from yeast processing. Measurements were conducted in a standard two-chamber glass MFC with a glass membrane separating the chambers. During the experiment, parameters such as start-up time, cell voltage during MFC start-up, output cell voltage, and power density curves were analyzed. The carbon paint-coated electrode with the activated coconut carbon additive demonstrated operating parameters similar to those of the carbon felt electrode. The results indicate that it is possible to produce electrodes (on a base of by-product of coconut processing) for MFCs using a painting method; however, to achieve a performance comparable to carbon felt, the addition of activated coconut carbon is necessary. This study demonstrates the feasibility of forming a biocompatible layer on various surfaces. Incorporating activated coconut carbon does not complicate the anode fabrication process, as fine ACC grains can be directly applied to the wet carbon paint layer. Additionally, the use of carbon paint as a conductive layer for the active anode in MFCs offers versatility in designing electrodes of various shapes, enabling them to be coated with a suitable active and conductive layer to promote biofilm formation. Moreover, the findings of this study confirm that waste-derived materials can be effectively utilized as electrode components in MFC anodes. The results validate the chosen research approach and emphasize the potential for further investigations in this field, contributing to the development of cost-efficient electrodes derived from by-products for MFC applications.

NiMoS-Modified Carbon Felt Electrode for Improved Efficiency and Stability in a Neutral S/Fe Redox Flow Battery

Polysulfide-ferricyanide redox flow batteries (PFRFBs) are gaining significant attention in long-duration energy storage for their abundant availability and environmental benignity. However, the sluggish kinetics of the polysulfide redox reactions have tremendously constrained their performances. To address this issue, we developed a NiMoS catalyst-modified carbon felt (NiMoS-CF) electrode, which significantly accelerates the electrochemical reaction rates and enhances the cycling stability of PFRFB. Our PFRFB system, integrated with the NiMoS-CF electrode, exhibited an energy efficiency of 70% and a voltage efficiency of 87%, with a remarkable doubling of its cycle life as opposed to the pristine carbon felt (CF) electrode at a current density of 40 mA cm−2. Notably, during 2500 cycles of charge–discharge testing, we achieved an average coulombic efficiency exceeding 99%. These improvements in PFRFB performance can be attributed to the NiMoS-CF electrode’s large surface area, low resistance, and robust redox activity. This study offerings a novel approach for enhancing the electrochemical reaction kinetics and cycling stability in PFRFBs, laying a scientific foundation in the applications of practical PFRFBs for next-generation energy storage.

Immobilization of FDH on carbon felt by affinity binding strategy for CO2 conversion

Immobilization of FDH on carbon felt by affinity binding strategy for CO2 conversion

UV-activated TiO₂-coated carbon felt for photocatalytic dye degradation and antibacterial applications

UV-activated TiO₂-coated carbon felt for photocatalytic dye degradation and antibacterial applications

Functional nano-carbon layer decorated carbon felt electrode for vanadium redox flow batteries

Functional nano-carbon layer decorated carbon felt electrode for vanadium redox flow batteries

The mechanism of Co-based carbon felt flow-through cathode non-homogeneous electro-Fenton system for organic pollutants degradation

The mechanism of Co-based carbon felt flow-through cathode non-homogeneous electro-Fenton system for organic pollutants degradation

Ni(0) formation on carbon felt cathode triggers redox synergetic degradation of Ni-EDTA during electrochemical treatment for Ni-plating wastewater.

Ni(0) formation on carbon felt cathode triggers redox synergetic degradation of Ni-EDTA during electrochemical treatment for Ni-plating wastewater.

Surface modification of carbon felt electrodes with SnO2 nanocoatings by using the SILAR method for enhanced performance in vanadium redox flow batteries

Surface modification of carbon felt electrodes with SnO2 nanocoatings by using the SILAR method for enhanced performance in vanadium redox flow batteries

Bio-electro-fenton system assisted with metal–organic framework for degradation of bis-phenol S in wastewater as an emerging contaminant

The bio-electro-fenton (BEF) system is a novel technology that can be utilized to degrade both emerging and persistent pollutants while producing clean, green, and sustainable energy. Various catalysts that have a high active surface area are employed in these systems to enhance the oxygen reduction reaction (ORR) efficiency. In this study, the Nickel/Cobalt metal–organic framework (Ni/Co BTC-MOF) as heterogeneous catalyst was synthesized and deposited by the cathodic electrochemical deposition method on the carbon felt (CF) and graphite plate (GP) electrodes. The results of FT-IR, Field Emission Scanning Electron Microscopy (FE-SEM), X-ray Diffraction (XRD), and Energy Dispersive X-ray spectroscopy (EDS) analysis proved that the synthesis of Ni/Co-BTC MOF successfully carried out. The performance and positive effect of the modified electrodes in ORR were investigated and compared in electrical energy generation. Finally, bio-electro-degradation of bisphenol-S (BPS) as one of the endocrine-disrupting compounds (EDCs) was studied by the optimal modified electrode. According to the results of electrochemical experiments, the highest maximum power density is equal to 133.6 mW/m2, which is related to Ni/Co-BTC@CF, and the highest production voltage is related to Ni/Co-BTC@CF, Ni/Co-BTC@GP, CF, and GP, respectively. The removal efficiency levels of bisphenol S in this system at different concentrations of 1.0, 5.0, and 10.0 mg/l after 24 h were 98.0%, 84.0%, and 41.0%, respectively. Based on the obtained results, the improved BEF system with Ni/Co-BTC@CF catalyst can be a suitable technology to achieve more electricity flow and at the same time have a positive effect on the decomposition of bisphenol S pollutant.

Sn(II)-Pyrophosphate Complex with Low Plating/Stripping Potential for Sn-I Flow Battery Applications.

Exploring electrolyte formulations that can effectively reduce the plating/stripping potentials of metallic electrodes holds great significance in advancing the development of high-voltage redox flow batteries. In this study, we introduce a novel Sn-based chelated electrolyte, namely, Sn(P2O7)26-, by directly reacting the Sn2+ solution with an excess of P2O74- solution. Electrochemical tests prove that the incorporation of high-concentration P2O74- ligands could shift the plating/stripping potential to -0.67 V. Thus, the demonstrated Sn-I flow battery reveals an average cell voltage of nearly 1.2 V and maintains stable cycling over 250 cycles at a high current density of 80 mA cm-2, with an average energy efficiency of about 70%. Moreover, no dendrite formation formed during the Sn deposition on the carbon felt. This study offers broad prospects for the future development of high-voltage Sn-based flow batteries.

Achieving Highly Reversible Mn2+/MnO2 Conversion Reaction in Electrolytic Zn‐MnO2 Batteries via Electrochemical‐Chemical Process Regulation

Despite the widespread interest in electrolytic Zn‐MnO2 batteries with excellent output voltage and high theoretical capacity, the spontaneous disproportionation reaction of free Mn3+ along with the disorderly deposited inactive MnO2 results in the low Mn2+/MnO2 conversion reversibility, which seriously affects their cycling stability. Here, we propose a novel aqueous SiO2 colloidal electrolyte with FeSO4 mediator (denoted as SF electrolyte) based on a bidirectional electrochemical‐chemical model to achieve dual regulation of the MnO2 deposition/dissolution process. During the charging process, the SiO2 colloidal particles located at the carbon felt interface and the electrolyte bulk phase simultaneously provide sufficient disproportionation sites for the diffused Mn3+ to guide the orderly rapid deposition of MnO2. Meanwhile, the introduction of Fe2+ mediators during the discharge process can sufficiently react with MnO2 on the SiO2 particles in the electrolyte, thereby further enabling the efficient conversion of Mn2+/MnO2. Consequently, electrolytic Zn‐MnO2 battery with SF electrolyte can stably run for 550 cycles at 10 mA h cm‐2 and achieve superior reversibility at a high area capacity of 20 mA h cm‐2. This work demonstrates the feasibility of colloidal electrolytes in modulating electrochemical‐chemical processes to stabilize electrolytic Zn‐MnO2 batteries.

Achieving Highly Reversible Mn2+/MnO2 Conversion Reaction in Electrolytic Zn-MnO2 Batteries via Electrochemical-Chemical Process Regulation.

Despite the widespread interest in electrolytic Zn-MnO2 batteries with excellent output voltage and high theoretical capacity, the spontaneous disproportionation reaction of free Mn3+ along with the disorderly deposited inactive MnO2 results in the low Mn2+/MnO2 conversion reversibility, which seriously affects their cycling stability. Here, we propose a novel aqueous SiO2 colloidal electrolyte with FeSO4 mediator (denoted as SF electrolyte) based on a bidirectional electrochemical-chemical model to achieve dual regulation of the MnO2 deposition/dissolution process. During the charging process, the SiO2 colloidal particles located at the carbon felt interface and the electrolyte bulk phase simultaneously provide sufficient disproportionation sites for the diffused Mn3+ to guide the orderly rapid deposition of MnO2. Meanwhile, the introduction of Fe2+ mediators during the discharge process can sufficiently react with MnO2 on the SiO2 particles in the electrolyte, thereby further enabling the efficient conversion of Mn2+/MnO2. Consequently, electrolytic Zn-MnO2 battery with SF electrolyte can stably run for 550 cycles at 10 mAh cm-2 and achieve superior reversibility at a high area capacity of 20 mAh cm-2. This work demonstrates the feasibility of colloidal electrolytes in modulating electrochemical-chemical processes to stabilize electrolytic Zn-MnO2 batteries.

Sustainable One-Pot Electrochemical Approach for Entrapment of Multi-Enzymes and Biocompatible Redox Mediator.

Enzyme immobilization is regarded as a key factor for their effective utilization in various fields such as biofuel production, wastewater treatment, and biosensors. Designing new electrodes with biocompatible support matrices is essential to improve the stability in bioelectrocatalysis. Modified carbon felt electrodes were prepared and tested as bioelectrocatalyst under mild conditions - aqueous media at room temperature and basically neutral pH. Co-immobilization of dehydrogenase enzymes and neutral red (NR) dye at carbon felt electrodes was successfully achieved during electropolymerization of pyrrole in a facile one-step approach. Neutral red was incorporated to operate as a redox mediator supporting efficient electron transfer to the enzymes' active sites. Electrodes modified with alcohol dehydrogenase (ADH) have been employed to reduce acetaldehyde to ethanol in a chronoamperometic setting with Faradaic efficiency (FE) of up to 33 %. By incorporating the cascade reaction with three enzymes - ADH, formate dehydrogenase, and formaldehyde dehydrogenase - an electroreduction sequence could be established to produce methanol from CO2 reaching a FE of 10 %. The proposed approach shows good stability. Together with the simple implementation and application, this process is promising for employment in enzymatic electrocatalysis.

Screening Refractory Dye Degradation by Different Advanced Oxidation Processes.

This study investigated Rhodamine B (RhB) degradation by electro-Fenton (EF), anodic oxidation (AO), and their combination (EF/AO), using a carbon felt cathode coupled to a sub-stoichiometric titanium dioxide Magnéli phase (Ti4O7) anode or a platinized titanium (Ti/Pt) anode. The results indicated that operational parameters influenced the kinetics of electrochemical reactions. An increase in current density from 10 to 50 mA cm-2 significantly enhanced the RhB degradation rate; 30 mA cm-2 was the optimal current density, balancing both energy efficiency and degradation performance. Moreover, higher RhB concentrations required longer treatment. The Microtox® bioluminescence inhibition test revealed a significant toxicity decrease of the dye solution during electrochemical degradation, which was highest with EF/AO. Similarly, total organic carbon removal was highest with EF/AO (90% at pH 3), suggesting more efficient mineralization of RhB and its by-products than with EF or AO. Energy consumption remained relatively stable with all oxidation processes throughout the 480 min electrolysis period. High-resolution mass spectrometry elucidated RhB degradation pathways, highlighting chain oxidation reactions leading to the formation of intermediates and mineralization to CO2 and H2O. This study underscores the potential of EF, AO, and EF/AO as effective methods for RhB mineralization to develop sustainable and environmentally friendly wastewater treatment strategies.

FeOOH-CoFe layered double hydroxide carbon felt cathode for the electro-Fenton degradation of oxytetracycline in aqueous solution

ABSTRACT Heterogeneous electro-Fenton is one of green and promising technologies for removing organic pollutants. In this paper, the FeOOH-CoFe layered double hydroxide carbon felt (LDH/CF) was synthesized by a facile hydrothermal method for an efficient degradation of oxytetracycline (OTC). The structural morphology and elemental composition of the composite electrode were studied by scanning electron microscopy, X-ray diffractometer, and X-ray photoelectron spectroscopy. Then, the electrocatalytic activity of the composite electrode was analysed through electrochemical characterization such as cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy. The removal rate of 20 mg/L OTC reached about 91.6% at pH = 3, with a current density of 6.67 mA cm−2 within 60 minute in the hydrophobic FeOOH-CoFe LDH/CF + PTFE system. Moreover, the catalytic electrode exhibited impressive degradation efficiency over a wide pH range. According to quenching experiments, the principal reactive oxygen species (·O2 -, ·OH, and 1O2) involved in the degradation of OTC was identified. Based on this discovery, the possible mechanism for the degradation of OTC was also proposed. In addition, the cyclic experiment demonstrated relatively excellent stability of the hydrophobic FeOOH-CoFe LDH/CF + PTFE electrode, which provided the possibility for the practical application of the electrode.

Carbon filter layer for respirator derived from acrylic filter felt.

Carbon filter layer for respirator derived from acrylic filter felt.

Anodic oxidation using 3D carbon felt/PbO2 anode: a electron transfer-mediated system for degradation of Rhodamine B

ABSTRACT This study investigates the use of porous structured carbon felt (CF) as a substrate for the preparation a lead dioxide (CF/PbO2) anode for the electrochemical oxidation of Rhodamine B (RhB). Compared to traditional titanium-based lead dioxide (Ti/PbO2) and graphite sheet-based lead dioxide (GS/PbO2) anodes, the CF/PbO2 anode exhibited superior electrocatalytic activity, achieving a RhB degradation efficiency exceeding 99%. After 10 cycles, the electrocatalytic activity of CF/PbO2 anode remained robust, with a degradation efficiency of over 97%. Fluorescence spectroscopy, quenching experiments, and electrochemical tests indicate that the electrochemical oxidation behaviour on CF/PbO2 and GS/PbO2 anodes was governed by direct electron transfer, while indirect oxidation via •HO radicals was pivotal for the Ti/PbO2 anode. LC-MS analysis identified the intermediates of RhB degradation, contributing to the proposed degradation pathway. This study provides an efficient anode for the electrochemical degradation of organic pollutants in water.

A NiCo2O4 nanowire arrays decorated carbon felt cathode for synergistic treatment of complex uranium-organic wastewater in a self-driven solar coupling system

A NiCo2O4 nanowire arrays decorated carbon felt cathode for synergistic treatment of complex uranium-organic wastewater in a self-driven solar coupling system