Carbon Black Electrodes Research Articles

Environmentally Benign Synthesis of Magnetic Fe3O4 Nanoparticle/Carbon Black/Copper‐Quercetin Rods for Sensitive, Disposable Electrochemical Sensor for Mitoxantrone

AbstractPhenolic compounds have a variety of activities but are most famous for their antioxidant and metal‐chelating properties. We explore the green synthesis and application of Fe3O4 nanoparticles, carbon black (CB), and copper‐quercetin (Cu−Q) composite for a disposable electrochemical sensor for mitoxantrone. Fe3O4 was synthesised using Camellia sinensis leaf extract. The copper‐quercetin was synthesised by titrating copper acetate solution with quercetin monohydrate solution at room temperature. Equal amounts of Fe3O4, CB, and Cu−Q were mixed to form Fe3O4‐CB/Cu−Q. The Fe3O4‐CB/Cu−Q/SPE has the lowest detection limit (55.47 pM) compared to previous mitoxantrone sensors. The average recovery was 102.2 %, with an RSD of 4.67 % in serum. The sensor maintained an average accuracy of 98.99 % in the presence of the interfering agent. The detection limit of the new sensor is about five times lower than that of the previous Fe3O4 and carbon black electrode. Therefore, it can be suggested that the Copper‐quercetin complex contributed significantly to the electrode's sensitivity. This research is the first to report the three oxidation potentials for mitoxantrone consistent with mitoxantrone's complex oxidation mechanism. Also, this is the first report on using copper‐quercetin as an electrode material for electrode chemical detection. Furthermore, this is the first green‐derived sensor for mitoxantrone.

A novel poly(Rhodamine B) coated polylactic acid doped carbon black electrode for nitrite detection in drinking water

A novel poly(Rhodamine B) coated polylactic acid doped carbon black electrode for nitrite detection in drinking water

Electrosynthesis and characterization of poly(rhodamine B) coatings on 3d printed polylactic acid doped carbon black (PLA-CB) electrodes for promising sensor applications

Electrosynthesis and characterization of poly(rhodamine B) coatings on 3d printed polylactic acid doped carbon black (PLA-CB) electrodes for promising sensor applications

Exploiting a carbon black paste electrode modified with palladium nanoparticles entrapped in aluminum hydroxide matrix for selective detection of 2(3)-t-Butyl-4-hydroxyanisole antioxidant in biodiesel samples

A simple and selective method for determination of 2(3)-t-Butyl-4-hydroxyanisole (BHA) based on carbon black (CB) paste electrode modified with Palladium nanoparticles entrapped in aluminum hydroxide matrix (PdNPAH) is described for the first time. The materials were characterized by Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The composition of the paste was studied using different amounts of each material. The voltammetric studies of the behavior of BHA on PdNPAH/CBP electrode demonstrated a catalytic activity for the oxidation process of BHA. Also, the voltammetric studies showed that it is possible to determine BHA in presence of 3,5-Di-tert-butyl-4-hydroxytoluene (BHT) and 2-(1,1-Dimethylethyl)-1,4-benzenediol (TBHQ). Under optimized conditions, the method showed a linear response for BHA from 1-5000 µmol/L and a detection limit of 0.20 µmol/L. The proposed method presented good selectivity, precision and it was successfully applied for detection of BHA in biofuel with recovery values from 98.80 % to 105.29 %, showing a good accuracy for the proposed method.

Understanding the Effect of Lithium Nitrate as Additive in Carbonate-Based Electrolytes for Silicon Anodes

Due to its high specific capacity, silicon is one of the most promising anode materials for next-generation lithium-ion batteries. However, its large volumetric changes upon (de)lithiation of ∼300% lead to a rupture/re-formation of the solid-electrolyte interphase (SEI) upon cycling, resulting in continuous electrolyte consumption and irreversible loss of lithium. Therefore, it is crucial to use electrolyte systems that form a more stable SEI that can withstand large volume changes. Here, we investigate lithium nitrate (LiNO3) and lithium nitrite (LiNO2) as electrolyte additives. Linear scan voltammetry on carbon black working electrodes in a half-cell configuration with LiNO3-containing 1 M LiPF6 in EC/DEC (1/2 v/v) revealed a two-step reduction mechanism, whereby the first reduction peak could be attributed to the conversion of LiNO3 to LiNO2, while X-ray photoelectron spectroscopy on harvested electrodes suggests the formation of Li3N during the second reduction peak. On-line electrochemical mass spectrometry (OEMS) on carbon black electrodes showed that N2O gas is evolved upon the reduction of LiNO3- and LiNO2-containing electrolytes but that the gassing associated with EC reduction is significantly reduced. Furthermore, OEMS and voltammetry were used to examine the redox chemistry of LiNO2 additive. Finally, LiNO3 and LiNO2 additives significantly improved the cycle-life of Si||NCM622 full-cells.

Surfactant-Driven Dynamic Changes in Rheology of Activated Carbon Slurry Electrodes.

Carbon black slurry electrodes are an effective means to improve flow battery performance by increasing the active surface area necessary for electrochemical reactions with a cost-effective material. Current challenges with this specific flow battery chemistry include the stability and flowability of the carbon black suspensions, especially in response to formulation choices. Advancing the manufacturing, operation, and performance of these redox flow batteries requires a deeper understanding of how slurry formulation impacts its rheological profile and ultimately battery performance. In response to this need, the linear and nonlinear rheological responses of activated carbon (AC) based slurry electrode materials used in an all-iron flow battery in the presence of a nonionic surfactant (Triton X-100) were measured. Results from these measurements show the slurry is a colloidal gel with elasticity remaining constant despite increasing surfactant concentration until α (= Csurf/CAC) < 0.65. However, at α ≥ 0.65, the slurry abruptly transitions to a fluid with no measurable yield stress. This critical surfactant concentration at which the rheological profile undergoes a dynamic change matches the concentration found previously for gel collapse of this system. Moreover, this transition is accompanied by a complete loss of electrical conductivity. From these data we conclude the site specific adsorption of surfactant molecules often used in slurry formulation has a significant and dramatic impact on the stability and flowability of these suspensions. Work presented herein demonstrates the importance of additive choices when formulating a slurry electrode.

Anisotropic, free-standing anodic films with aligned anatase-bronze TiO2-integrated graphene for high-capacity lithium-ion batteries

The composition modification and structure manipulation of carbon-based battery electrodes is becoming an increasingly urgent need for safer, more reliable, and effective electric vehicles. Herein, we fabricate a free-standing hybrid anatase-bronze TiO2-grafted reduced graphene oxide (TiO2-rGO) through a one-pot solvothermal procedure. The TiO2-rGO composite was transformed into a film with an anisotropic alignment and assembled as an anode into lithium-ion batteries (LIBs) to enhance its performance. Our previously developed “Pulse Freezing” process, with modifications including: (1) dimensional and structural optimization for larger and faster film production and (2) optimal microfluidic condition for vertical porous alignment, is utilized for assembling this nanocomposite anodic film. During the microfluidic assembly process, we achieved the desirable flowrate, flow patterns, and alignments of the integrated TiO2-rGO layers while forming porous microstructures through freeze drying. The porous and aligned TiO2-integrated rGO film exhibits a significantly enhanced specific capacity of 400 mAh/g at 0.2 A/g, which is a drastic increase compared to traditional TiO2 and carbon black electrodes possessing <50 mAh/g capacity, attributed to the anisotropic alignment and porous microstructure of rGO in combination with TiO2 grafting. The developed TiO2-rGO composite film provides a promising application of Ti-based electrodes in LIBs for commercial battery industries.

Gold particles modified 3D printed carbon black nanonetwork electrode for improving the detection sensitivity of dopamine

Using 3-dimensional (3D) printing to create a fast and accurate electrochemical sensor has attracted the attention of analytical scientists. This study utilized a carbon black/PLA composite filament as the raw material for the construction of 3D electrodes (3DEs). Au particles were modified onto the activated surface of the carbon black nanonetwork 3DE. The physical and chemical properties of the 3DEs were evaluated through scanning electron microscopy (SEM) and X-ray spectroscopy (XPS). Additionally, a range of electrochemical techniques were employed to investigate the electrochemical performance of the 3DEs. The sensor is capable of detecting DA in the concentration range of 0.01–20 μM with the limit of detection (LOD) of 0.084 μM. The approach is also capable of being applied to the actual sample detection of DA with excellent selectivity. Hence, the method of combining noble metal particles and carbon black nanonetwork for constructing 3DE presents novel prospects towards the creation of electrochemical sensors with exceptional sensitivity.

Electro-induced carbon black particle electrodes for sustainable tetracycline degradation

For the purpose of degrading tetracycline (TC), a three-dimensional electro-oxidation (3D EO) system using particle electrodes of carbon black (CB) and polytetrafluoroethylene (PTFE) was developed. The CB-PTFE particles fabricated at a CB/PTFE mass ratio of 3:2 and calcination time of 60 min exhibited the high performance for TC removal, as well as low energy consumption and high mechanical strength. TC removal efficiency reached 95% within 15 minutes, driven by a pseudo-first-order reaction with a rate constant of 0.20 min−1. The process incurred an energy consumption of 20.31 kWh/m3. The surface characterizations indicated that the CB-PTFE particles possessed excellent catalytic properties for H2O2 production. Despite the substantial influence of voltage and particle dosage on performance, the system demonstrated consistently high efficiency in TC removal regardless of solution pH within the range of 3–11. Quenching experiments and probe experiments using benzoate suggested that the surface-bound hydroxyl radicals (•OH (ads)) dominated (64.7%) the oxidation of TC in the 3D CB-PTFE EO system. The •OH (ads) was produced by the reduction of H2O2 on the particle surface. Products examination by LC-MS-MS confirmed a degradation pathway of TC by •OH attacking. These findings indicate that the CB-PTFE EO system has unique advantages and potentials in treating antibiotics due to its high oxidizing capacity, a wide range of applicable pH, no chemical adding, and self-cleaning.

One‐step preparation of binder‐free nickel‐containing graphene foam electrode for supercapacitors

AbstractIn this study, a nickel hydroxide (Ni(OH)2)‐modified reduced graphene oxide (rGO) foam electrode for supercapacitor application is presented. The electrode was prepared without using a binder through a one‐step process with three different ratios (NirGO1, NirGO2, and NirGo3). To compare the supercapacitor performance of the obtained graphene foam electrodes, rGO and rGO:carbon black (CB) standard electrodes with PVDF‐HFP binder were also prepared. All electrodes were then characterized structurally (XPS, EDS, RAMAN, XRD, and FT‐IR) and morphologically (SEM). Structural characterizations demonstrated that the Ni‐containing electrodes were in α‐Ni(OH)2:rGO structure. In addition, NirGO3 exhibited a specific capacitance of 800 F g−1 which is relatively the highest performance between the foam electrodes, while rGO:CB presented a specific capacitance of 900 F g−1. The results demonstrated that with the method proposed for electrode development, it was possible to obtain comparable results with the standard electrode rGO:CB.

Improved Hole Extraction and Band Alignment via Interface Modification in Hole Transport Material‐Free Ag/Bi Double Perovskite Solar Cells

Within one decade, lead halide perovskite solar cells have reached power conversion efficiencies (PCEs) compatible with that of silicon solar cells. While in the beginning, they suffered from short device lifetimes, those have also been strongly improved over time. However, their content of toxic lead still poses a risk of environmental pollution and human health on exposure. The double perovskite (DP) Cs2AgBiBr6 offers the potential to be a lead‐free alternative light‐harvesting material. Herein, the fabrication of hole transport material (HTM)‐free Cs2AgBiBr6‐based solar cells is presented, in which the DP surface is modified via a n‐butylammonium posttreatment to create a 2D/3D mixed interface. Additionally, the commonly utilized metal electrode and HTM are substituted with a carbon black back electrode (CBE) consisting of up‐cycled biowaste. Through the 2D/3D interface modification, charge recombination is suppressed, and band alignment is improved at the perovskite/CBE interface. Additionally, density functional theory calculations reveal that an increasing 2D modification thickness enhances the probability for holes in Cs2AgBiBr6 to be located close to the perovskite/CBE interface, further supporting their extraction. Overall, the PCE of the HTM‐free solar cells is improved through the implementation of a low‐cost and end‐of‐waste fabrication strategy.

An airbrush 3D printer: Additive manufacturing of relaxor ferroelectric actuators

The additive manufacturing of electroactive polymer (EAP) devices poses significant challenges due to their distinct structure and dissimilar properties of their constituent materials. It requires deposition of multiple functional materials with different properties, achieving μm-scale resolution in layer thickness, and executing incremental deposition and curing steps while preserving the previously deposited functional material layers. This study introduces an airbrush 3D printer concept and employs it for fabricating EAP transducers. An airbrush 3D printer was constructed by adapting a standard extrusion printer platform and integrating it with a two fluid atomizer (i.e. an airbrush) as the deposition tool. A process was developed for printing of the bending P(VDF-TrFE-CTFE) actuators with carbon black electrodes, and actuators with a single and dual EAP layers were fabricated. The airbrush printer attained in-plane resolution of 0.5mm, thickness resolutions of 0.63 μm and allowed atomizing up to 7% P(VDF-TrFE-CTFE) solutions. The 18 mm × 4 mm EAP actuators achieved 340μm (440 Vpp) and 3.7 mm (400 Vpp, 104 Hz) tip deflections respectively in quasi-static and resonant operation. Airbrush printing therefore proved to be a robust method for printing precursor materials with a wide range of properties, and is anticipated to be a versatile approach for printing other passive and stimuli-responsive materials and devices.

Evaluating diverse electrode surface patterns of 3D printed carbon thermoplastic electrochemical sensors.

Electrochemical sensing techniques rely on redox reactions taking place at the electrode surface. The configuration of this surface is of the utmost importance in the advancement of electrochemical sensors. The majority of previous electrode manufacturing methods, including 3D printing have produced electrodes with flat surfaces. There is a distinct potential for 3D printing to create intricate and distinctive electrode surface shapes. In the proposed work, 3D printed carbon black polylactic acid electrodes with nine different surface morphologies were made. These were compared to a flat surface electrode. To evaluate the performance of the electrodes, measurements were conducted in three different redox probes (ferrocene methanol, ferricyanide, and dopamine). Our findings highlighted that when electrodes were normalised for the geometric surface area of the electrode, the surface pattern of the electrode surface can impact the observed current and electron transfer kinetics. Electrodes that had a dome and flag pattern on the electrode surface showed the highest oxidation currents and had lower values for the difference between the anodic and cathodic peak current (ΔE). However, designs with rings had lower current values and higher ΔE values. These differences are most likely due to variations in the accessibility of conductive sites on the electrode surface due to the varying surface roughness of different patterned designs. Our findings highlight that when making electrodes using 3D printing, surface patterning of the electrode surface can be used as an effective approach to enhance the performance of the sensor for varying applications.

Electrochemical performance of electrophoretically deposited zinc antimony oxide–carbon black anode for lithium-ion batteries

Zinc antimony oxide (ZnSb2O6), a relatively new anode having a tri-rutile type of structure, is synthesized by a solution-based synthesis route. Zinc antimony oxide–carbon black (ZSO-CB) electrodes are fabricated by electrophoretic deposition technique. Regarding, film quality and mass loading, a 3-minute deposition period at 100 V applied potential is shown to yield optimized performance. When used as an anode for lithium-ion battery (LIB), these electrodes show a steady capacity of 464 mAhg−1 at a specific current of 500 mAg−1 after 400 cycles. It exhibits an excellent rate capability of 370 mAhg−1 at 4000 mAg−1 specific current, which is comparable to that of the theoretical capacity of commercial graphite anode (372 mAhg−1). ZSO can therefore be a potential anode for LIBs.

Soft composite actuators of poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene)-based nanofibers and polydimethylsiloxane: Fabrication, electromechanical characterization, and dynamic modeling

Nanofibrous unimorph cantilever beam soft actuators offer remarkable advantages, such as rapid viscoelastic relaxation, low power consumption, and high weight-specific properties. However, the presence of high porosity in the nanofibrous active layer poses a challenge due to its low breakdown voltage, limiting the practical applications of this class of soft actuators. This study proposes an innovative solution to enhance the relative permittivity of the nanofibrous layer by redesigning it as a composite layer. By integrating electrospun aligned nanofibers of poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) into a polydimethylsiloxane elastomeric matrix, the composite active layer achieves a notable increase in relative permittivity (10.5 at 100 Hz), surpassing the individual materials' values (2.5 and 2.7 at 100 Hz for the nanofibers and polydimethylsiloxane, respectively). To realize novel soft actuators, the composite active layer is placed between carbon black electrodes, with Kapton® serving as the passive layer. Remarkably, aligning the nanofibers in the transversal direction of the actuator enhances its actuation capabilities significantly. When subjected to a 25 MVm−1 electric field, the tip deflection and blocking force exhibit a ∼400% improvement compared to polydimethylsiloxane-based actuators. To support these findings, a physics-based dynamic model is derived and validated through experimental tests in both static and transient time simulations.

Biocompatible Gel-Free Coconut Oil and Carbon Black Electrodes for ECG and Respiration Measurements

The current state of the art in telemedicine has increased the interest in long term monitoring of physiological and bioelectric signals. This motivated the development of materials and techniques for the fabrication of biocompatible, user and environmentally friendly alternatives to conventional resistive wet electrodes. Here we report a method for the fabrication of dry flexible and stretchable electrodes based on Coconut-Oil and Carbon Black for the monitoring of electrophysiological signals without conductive gels. The highly stretchable material shows a specific resistance ρ down to 33.2±12.3Ωm, high conformability, and a stretchability up to 1500%. The epidermal electrodes were used to record Electrocardiographic (ECG) signals and measure respiration in a 3-lead configuration and compared to commercial wet electrodes. Even after being elongated by 100% for 100 stretch/release cycles, a reliable recording of the QRS-complex is demonstrated without the need for any contact enhancer or substances that cause skin reaction, demonstrating the potential use of this material for long term ECG monitoring applications.

Chloroplast-Inspired Carrier Circulation for Improved Photoelectrochemical Photodetectors Based on Ti2CTx Nanosheets.

Here, a photoelectrochemical (PEC) photodetector with good flexibility and high photoresponsivity was successfully fabricated in a vertical structure, where the MXene (Ti2CTx) nanosheet and carbon black electrode were separated by adenosine triphosphate/nicotinamide adenine dinucleotide phosphate (ATP/NADPH)-incorporated solid-state electrolyte. The photocurrent and photoresponsivity can reach 1.84 μA/cm2 and 8.89 μA/W, respectively, under a light intensity of 90 mW/cm2 at a bias potential of 0.6 V, which are approximately 2.3 times those of Ti2CTx nanosheets. The addition of ATP and NADPH to the electrolyte also leads to a large decrease of the rise time from 0.76 to 0.26 s. Furthermore, the photodetector can continue to function and maintain stability under 45° bending and after 500 cycles of bending, indicating a robust device structure and great flexibility. The performance enhancement of the PEC photodetector can be attributed to the synergistic effect of electrolyte additives on Ti2CTx nanosheets, where ATP and NADPH greatly enhance the circulation and utilization of photogenerated carriers. This work suggests that the incorporation of chloroplast-inspired carrier circulation with two-dimensional nanosheets could achieve efficient light-current conversion, providing a new strategy to improve the performance of PEC-type photodetectors.

Flexible Gel-Free Multi-Modal Wireless Sensors With Edge Deep Learning for Detecting and Alerting Freezing of Gait Symptom.

Freezing of gait (FoG) is a debilitating symptom of Parkinson's disease (PD). This work develops flexible wearable sensors that can detect FoG and alert patients and companions to help prevent falls. FoG is detected on the sensors using a deep learning (DL) model with multi-modal sensory inputs collected from distributed wireless sensors. Two types of wireless sensors are developed, including: 1) a C-shape central node placed around the patient's ears, which collects electroencephalogram (EEG), detects FoG using an on-device DL model, and generates auditory alerts when FoG is detected; 2) a stretchable patch-type sensor attached to the patient's legs, which collects electromyography (EMG) and movement information from accelerometers. The patch-type sensors wirelessly send collected data to the central node through low-power ultra-wideband (UWB) transceivers. All sensors are fabricated on flexible printed circuit boards. Adhesive gel-free acetylene carbon black and polydimethylsiloxane electrodes are fabricated on the flexible substrate to allow conformal wear over the long term. Custom integrated circuits (IC) are developed in 180 nm CMOS technology and used in both types of sensors for signal acquisition, digitization, and wireless communication. A novel lightweight DL model is trained using multi-modal sensory data. The inference of the DL model is performed on a low-power microcontroller in the central node. The DL model achieves a high detection sensitivity of 0.81 and a specificity of 0.88. The developed wearable sensors are ready for clinical experiments and hold great promise in improving the quality of life of patients with PD. The proposed design methodologies can be used in wearable medical devices for the monitoring and treatment of a wide range of neurodegenerative diseases.

Selection and optimization of carbon-based electrode materials for flow-electrode capacitive deionization

Flow-electrode capacitive deionization (FCDI) is an emerging desalination technology for its high desalination efficiency and continuous operation. This study systematically investigated the feasibility of various representative carbon-based materials and their combinations as the flow-electrode with the primary focus on their desalination efficiency and energy efficiency in FCDI. Among individual carbon-based electrode materials, namely activated carbon (AC), carbon fiber (CF), carbon black (CB), multi-walled carbon nanotubes (MWCNTs), and graphene nanoplatelets (GNPs), the nano-scale materials obviously outperformed micron-scale materials. Whereas, the combinations of AC + MWCNTs/GNPs provided superior desalination performance than AC + CB while working as blended flow-electrodes in FCDIs due to the different spatial configurations of three nano-scale particles. Furthermore, CB was tested as the base material in combination with MWCNTs and GNPs respectively. Approximately 110–130% increments in maximum salt adsorption rate were obtained for both blended electrodes compared to individual CB electrodes. The highest SARmax of 1.59 ± 0.02 μg cm−2 s−1 was observed in FCDI driven by the CB + GNPs electrode at a content of 1.5/0.5 wt%. Supported by the results of field emission scanning electron microscopy (FESEM) and electrical impedance spectroscopy (EIS), the 2D spatial morphologies of GNPs were able to build similar but more stable “bridges” between base electrode particles (i.e., AC or CB) as CNTs. Its sheet-like structure avoided agglomeration problems and largely promoted the conductivity of the product flow-electrodes.

Inactivation of Microcystis aeruginosa by H2O2 generated from a carbon black polytetrafluoroethylene gas diffusion electrode in electrolysis by low-amperage electric current

Frequent outbreaks of cyanobacterial blooms have seriously threatened aquatic ecological environments and human health. Electrolysis by low-amperage electric current is effective for algae inactivation; however, it has no selectivity. Hydrogen peroxide (H2O2) is considered to be an efficient and selective suppressor of algae. Therefore, it is necessary to develop an electrode that can generate H2O2 to improve electrolysis technology. In this study, a carbon black polytetrafluoroethylene gas diffusion electrode (C-PTFE GDE) with good stability was prepared by a simple adhesive coating method. Then, the inactivation of Microcystis aeruginosa was conducted with electrolysis by low-amperage electric current using Ti/RuO2 as the anode and C-PTFE GDE as the cathode. When the electrode spacing was 4 cm, the current density was 20 mA cm−2, and the gas flow was 0.4 L min−1, 85% of the algae could be inactivated in 20 min. Comparing the inactivation effect of the electric field and electrogenerated oxidants, it was found that electrolysis more rapidly and strongly inactivated algae when an electric field existed. However, electrogenerated oxidants dominated algae inactivation. The concentration of H2O2 was as high as 58 mg L−1, while the concentration of chlorines was only 0.57 mg L−1, and the generation rate of H2O2 was 65 times that of chlorines. Consequently, electrogenerated oxidants dominated by H2O2 attacked photosystem II of the algae and caused oxidative damage to membrane lipids, affecting the photosynthetic capacity. Eventually, most of the algae were inactivated. The study suggested that C-PTFE GDE was promising for the inactivation of Microcystis aeruginosa in this electrochemical system.