Metal oxide-based modifiers have been identified as a promising material to improve the overall sensitivity, selectivity and versatility of electrochemical sensors. The electrochemical sensing of an anthranilic acid derivative called mefenamic acid (MFA) was investigated in the present work using copper doped tungsten oxide (Cu–WO3) as an electrode modifier and its application for possible clinical analysis. The Cu–WO3 modified carbon paste electrode (CPE) was developed and optimized for electrochemical sensing of MFA. The cetyltrimethylammonium bromide (CTAB) presence improved the sensor’s sensitivity and selectivity while detecting MFA at trace levels which is essential for environmental and pharmaceutical analysis. The voltammetric study showed that the Cu–WO3/CTAB/CPE has great ability to electrochemically oxidize the MFA than bare and WO3 modified electrodes and the peak current of the reaction increased five times more than that of the unmodified electrode. The study exhibited impressive redox behaviour of MFA by the improvement of the characteristics of the surface and the effectiveness of charge transfer. The Cu–WO3/CTAB/CPE showed a low limit of detection (LOD) of 1.26 nM for a concentration range of 0.01–2.5 µM under optimal experimental conditions. The electrode was employed for the analysis of MFA in spiked urine samples and pharmaceutical tablets, achieving recovery rates of approximately 98
Sintered NdFeB magnets underpin advanced technologies yet remain acutely vulnerable to chloride induced corrosion. This study systematically investigates the time-resolved corrosion behaviour and mechanisms of single Ni and multilayer Ni–Cu–Ni electrodeposited coatings on NdFeB substrates during 240 h immersion in 3.5 wt
B-doping of the graphene framework is feasible for electrochemical applications as it facilitates the charge transfer between the neighbouring carbon atoms owing to its p-type semiconducting characteristics. The energy storage capabilities of EDLC materials in multiple redox additives are highly promising and becoming popular. This study discusses the advancement of reduced graphene oxide with doped boron for electrochemical sensing and energy storage. The optimized combination realized a specific capacitance of 395 F g− 1 at 0.5 A g− 1 in aqueous electrolyte. Further, the symmetric cell exhibited an improved energy density (46.5 Wh kg− 1) in H2SO4 solution (1 M) with triple redox mediators at 3 A g− 1. Additionally, the electrochemical sensing behavior of boron-doped reduced graphene oxide incorporated glassy carbon electrode (BGO/GCE) in 2,4-dinitrotoluene (DNT) is presented. Indeed, The BGO-2/GCE demonstrates superior sensing capabilities, with a minimal detection threshold of 18 nM across a linear dynamic range of 0.1–30.0 µM with commendable repeatability and stability.
Nanoplastic residues are a growing global concern for both aquatic and terrestrial ecosystems owing to their enduring harmful effects on the environment and the health of exposed organisms. This necessitates an ingenious research approach to develop a facile, multiplexed and sensitive detection for reliable analysis of these pollutants in real samples. Among the diverse molecules categorized under the taxonomic term “Nanoplastic residues”, this research focused on the simultaneous and sensitive electrochemical detection of two specific phenolic pollutants: hydroquinone and catechol. It explored the simultaneous electrochemical sensing, using fine ceria, CeO2 nanoparticles uniformly dispersed on reduced graphene oxide sheets. The synergistic effect of the nanoelectrocatalyst enhanced the selective molecular interactions and conductivity. A detailed analysis of the chemical and structural nature of the nanoelectrocatalyst was evaluated using the various physico-chemical characterization techniques. Furthermore, the evaluated sensor demonstrated a wide linear detection range of 5 – 220 µM for hydroquinone and 10 – 400 µM for catechol, with two distinct linear regions (10 – 200 µM and 250 – 400 µM) for catechol, and detection limits of 1.20 µM and 1.91 µM, respectively. The sensor’s selectivity amidst various interferents showed <5
Electrochemical detection of para-hydroxybenzoic acid has been reported in this work using a metalloporphyrin-based conjugated microporous polymer-modified glassy carbon electrode. This study sought to design, synthesize, and investigate the influence of different central metals (Zn, Ni, Co) in porphyrin-based conjugated microporous polymers toward para-hydroxybenzoic acid detection. The 2,2ꞌ-bithiophene-5,5ꞌ-dicarbaldehyde, as an organic linker, was incorporated into the polymer to provide additional conductivity or electron transport within the conjugated system, overcoming the aggregation limitation of the metalloporphyrin monomers. Cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse voltammetry techniques were employed to characterize the electrochemical behaviour and sensing properties of the modified electrodes. Under optimized experimental conditions, the fabricated cobalt(II)porphyrin conjugated microporous polymer sensor exhibited two linear segments in the ranges of 5.0–25 µM and 30–140 µM, achieving the detection limits of 0.133 µM and 0.244 µM, respectively. The modified electrode further demonstrated a high sensitivity value of 0.654 µM−1 cm−1, and good recoveries > 94.3
Simple and rapid electrode manufacturing techniques are crucial for promoting the commercial application of layered double hydroxide electrode materials. Compared with traditional chemical reduction methods or strategies for preparing oxygen vacancies in a three-electrode system, a simpler two-electrode route was adopted in this work. First, a nickel–cobalt layered double hydroxide precursor was constructed on nickel foam by constant-current electrodeposition in a two-electrode setup. Subsequently, by swapping the positions of the positive and negative electrodes and applying a short-term reverse current treatment for 5–25 s, oxygen-vacancy-rich nickel–cobalt layered double hydroxide was prepared in situ, achieving simultaneous morphological optimization and defect regulation. The sample treated with reverse current for 10 s exhibited a nanoflower structure densely distributed on nanosheets; its specific surface area was increased by 29.6
The current study focused on the design and optimization of electroactive materials for energy storage purposes. The preparation of a novel series of (MXene)x(NiO)1−x nanocomposite electrodes (where x = 1, 0.75, 0.50, 0.25, 0), prepared in varying stoichiometric ratios, was presented, which exhibited exceptional performance as supercapacitor electrodes. Detailed structural and morphological characterizations were performed to gain insight into the underlying physical properties of the composites. Electrochemical performance was systematically evaluated using cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The optimized electrode delivered a high energy density of 17.7 Wh kg− 1 and a power density of 450 W kg− 1 in a three-electrode setup. Additionally, it displayed impressive cyclic stability, retaining 85
The safety behaviors of Lithium-Ion Batteries are critical for public safety and economic development. However, the thermal runaway behaviors of LIBs, especially under the coupled environment of complex abuse conditions, are not fully understood. Herein, we systematically trace the safety behaviors of LIBs with an energy of 20 Wh, which is assembled with Graphite/Silicon composite anode and LiCoO2 cathode, that undergo a series of coupled abuse conditions, such as overcharge extrusion, temperature circulating storage extrusion, fast charging extrusion, thermal abuse extrusion. The ultimate extrusion force, deformation amount, highest TR temperature, and evolutionary images of safety behaviors of cell are reported and their relationships are analyzed. Batteries operating under different coupling conditions undergo various changes in their internal structure and substances, exhibiting distinctly different safety performances. This study demonstrates that relying solely on fresh-cell safety standards implemented at product launch cannot accurately evaluate the full-lifecycle risk of lithium-ion batteries.
The production of standard LFP electrodes involves the use of the toxic and costly solvent N-methylypyrrolidone (NMP) to dissolve polyvinylidenfluoride (PVDF), raising environmental and wellbeing concerns. This study advanced the use of water-based binders carboxymethylcellulose/styrene-butadiene rubber (CMC/SBR) as a replacement. Furthermore, compatibility with ionic liquid-based electrolytes, which potentially offer enhanced safety, were studied. LFP | Li half and LFP | LTO full cells assembled with an EC: DMC (1:1) + 1 M LiPF6 electrolyte demonstrated a specific capacity of (115 ± 5) mAh g− 1 at a 1 C rate over 100 cycles for the latter, and a capacity of (116 ± 0.7) mAh g− 1 was found during 10 cycle rate testing at the 1 C step in LFP | Li half-cells. Additionally, the LFP cathode exhibited notable compatibility with ionic liquids, achieving a specific capacity of (135 ± 2.5) mAh g− 1 with P14TFSI/20 wt
The development of cost-effective catalysts to accelerate the hydrogen evolution reaction has remained a challenge in past decades to realize the hydrogen economy. Electrochemical methanol reformation has evolved as a cost-effective and efficient technology for on-site hydrogen production. Herein, Graphene-supported palladium–iron electrocatalysts were synthesized using a chemical reduction method. The synthesized electrocatalysts were characterized structurally and morphologically using Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and thermogravimetric analysis. The electrocatalytic activity and production of hydrogen were explored using electrochemical techniques such as cyclic voltammetry, electrochemical impedance spectroscopy, and linear sweep voltammetry. Electrochemical studies revealed that 3:1 ratio of palladium -iron supported graphene exhibited a large electrochemically active surface area (101 m2 g−1), good long-term stability, low Tafel slope value (46 mV dec−1) and small Rct value (13 Ω). The practical application of the proposed catalyst was evaluated in a proton exchange membrane based single electrochemical methanol reformation cell. The synthesized 3:1 ratio of palladium -iron supported graphene electrocatalyst exhibited superior cell performance for 50 h at 60 °C, a cell voltage and current density of 0.57 V and 150 mA cm−2 respectively.The results indicated 3:1 ratio of palladium -iron supported graphene electrocatalyst as a cathode electrode could be the better choice for hydrogen evalution reaction in the electrochemical methanol reformation cell.
This study systematically investigated the interplay between material preparation parameters and electrochemical performance to advance the development of high-performance iron–air batteries for large‑scale energy storage. Seven iron powder samples with distinct particle‑size ranges (0–15 to 90–105 μm) were fabricated via gas atomization. The influences of particle‑size distribution and conductive‑agent type (carbon black, carbon nanotubes, graphene) on the reaction kinetics of the iron electrode were elucidated through a comprehensive set of physicochemical characterizations and electrochemical analyses. It was demonstrated that a synergistic combination of 30–45 μm iron powder and a carbon black conductive agent in a neutral K2SO4 electrolyte delivered superior performance, enabling a lab‑scale static battery to cycle stably for 333 h (1000 cycles) at 0.5 mA cm–2 with a low voltage gap of 0.64 V. Furthermore, the optimized material system was successfully scaled into a practical flow battery prototype that delivered a stable stack open-circuit voltage of 2.5–2.7 V, powers small electronic devices, and maintains energy efficiency above 40
Aqueous supercapacitors can be vastly superior in both the lowest and the highest operating temperatures, as well as output power, to modern non-aqueous devices through the use of appropriate low-temperature aqueous electrolytes and metal-free carbon electrodes. However, a shift to low-temperature aqueous supercapacitors is constrained by their elevated self-discharge caused by leakage currents arising from the anodic oxidation of carbon electrodes and electrolyte decomposition. This study was aimed at exploring self-discharge in supercapacitors based on low-temperature aqueous electrolytes, which freeze at temperatures below −70 °C and boil at temperatures above +100 °C, and freestanding carbon nanotube cloth electrodes affording low electrical resistivity of ca. 15 µΩ m, material capacitance of ca. 80 F g−1 as well as specific surface area exceeding 200 m2 g−1. The effects of carbon crystal lattice ordering and carbon surface functionalization on carbon nanotube cloth corrosion currents were analyzed in that connection. In order to establish maximum operating potential windows for carbon nanotube cloth materials in low-temperature aqueous electrolytes, the ring-disk electrode was used. Finally, the most promising low-temperature aqueous electrolyte to carbon nanotube cloth electrodes for real practical supercapacitor applications was proposed in the work.
Aqueous zinc-ion batteries (AZIBs) have aroused extensive research interest owing to their superior safety, environmental benignity, and low cost. Among various cathode candidates, manganese-based materials stand out prominently by virtue of the natural abundance, cost effectiveness, and high theoretical specific capacity, thereby emerging as one of the most intensively investigated cathode systems. Nevertheless, the intrinsic low electrical conductivity and severe Mn dissolution of pristine Mn2O3 result in sluggish reaction kinetics and drastic capacity fading upon prolonged cycling, which severely restrict their practical implementation. To address this issue, three-dimensional porous sulfur-doped Mn2O3 microspheres (SMO) are synthesized to suppress Mn leaching and enhance electrical conductivity. S possesses a large covalent radius and low electronegativity, which facilitates electron transport within the structure and enhances the conductivity of cathode materials. Results demonstrate that SMO electrode achieves a specific capacity of 179.4 mAh g− 1 (0.2 A g− 1). At 1 A g− 1, after 800 cycles, it exhibits a coulombic efficiency of 99.73
The possibility of using various polymeric binders (polyvinylidene fluoride, styrene-butadiene rubber, acrylonitrile multi-copolymer (LA133) and sodium carboxymethyl cellulose, sodium alginate, sodium polyacrylate), as well as sucrose as carbon sources for coating silicon anodes was investigated. The resulting Si/C composites based on silicon microparticles were characterized by XRD, Raman spectroscopy, SEM, CHN analysis, EIS and cyclic voltammetry; their electrochemical performance was tested. Superior performance was achieved for the Si/C composite produced using styrene-butadiene rubber as a carbon source, yielding a final carbon content of 5 wt
Lithium metal batteries are regarded as promising candidates for next-generation high-energy-density storage systems; however, their practical application is severely hindered by unstable lithium deposition and dendrite growth, especially under high current density conditions. Herein, a lithium-exchanged zeolite-modified separator that enables regulated Li+ transport and stabilizes lithium metal anodes was reported. Through a controlled ion-exchange process, Li+ is introduced into the zeolite channels, generating Li+-accessible sites and continuous ion transport pathways. The resulting Li-exchanged zeolite interlayer promotes homogeneous Li+ flux distribution and alleviates localized ion depletion during cycling. As a result, lithium metal cells equipped with the modified separator exhibit significantly enhanced cycling stability, maintaining stable operation over 1600 h at10 mA cm− 2 and 10 mAh cm− 2, along with reduced polarization and dendrite-free lithium deposition behavior. Furthermore, NCM||Li full cells demonstrate remarkable rate capability (15 C) and cycling stability, with low-capacity decay rates of 0.06
Metal-based sulfides have been attracting attention as electrode materials for energy storage since they possess tunable redox properties and abundant availability. However, the mechanism of charge storage of the metal sulfides has not been extensively studied for energy storage applications. In this work, cobalt sulfide (CoS), nickel sulfide (NiS), and copper sulfide (CuS) nanostructures are synthesized by the hydrothermal method. Structural, vibrational, and morphological properties were analysed by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and scanning electron microscopy (SEM). EDX elemental mapping confirmed the uniform distribution of elements. Electrochemical behaviour is assessed by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). Among the three nanostructures, CoS exhibits excellent electrochemical performance, achieving a high specific capacitance of 1501.61 F g− 1 at 1 mA g− 1. Furthermore, an asymmetric CoS//ASC device is fabricated, which demonstrates a maximum energy density of 70.29 Wh kg− 1, a power density of 395.22 W kg− 1, along with outstanding long-term stability and 94.76
Perovskite–carbon composite electrodes are widely used as bifunctional catalysts for oxygen reactions; however, their electrochemical behavior and underlying reaction pathways under operating conditions remain unclear. In this study, composites consisting of Sr2Co0.8Fe0.2O3Cl or LaCoO3 combined with amorphous KETJENBLACK and partially graphitized TOKABLACK were systematically investigated in alkaline media. Rotating disk electrode measurements showed that the KETJENBLACK-based composites exhibited higher oxygen reduction activity and a quasi-four-electron pathway, whereas the TOKABLACK-based composites followed a mixed two-electron process. For the oxygen evolution reaction, although KETJENBLACK+Sr2Co0.8Fe0.2O3Cl displayed higher initial activity, rapid performance degradation occurred during cycling and chronopotentiometry, whereas TOKABLACK+Sr2Co0.8Fe0.2O3Cl exhibited superior durability. X-ray photoelectron spectroscopy suggested that the degradation was mainly associated with the accelerated oxidation of the carbon support. The replacement of Sr2Co0.8Fe0.2O3Cl with LaCoO3 significantly suppressed the degradation of KETJENBLACK-based composites, indicating that the stability of perovskite–carbon composites may be influenced by perovskite-dependent interfacial interactions. These results demonstrated that both the carbon structure and catalyst identity govern the activity and durability of perovskite–carbon composites and should be carefully considered in electrode design.
The Al2O3 nanomaterial was produced using the combustion synthesis method, and its properties were characterized using X-ray Diffraction, Field Emission Scanning Electron Microscopy, and Energy Dispersive X-ray Analysis. This work involves preparing the electrochemical sensor with carbon paste electrodes to detect Sunset Yellow and Tartrazine, the major synthetic food dyes. Sunset Yellow and Tartrazine can be potentially carcinogenic if consumed excessively above the recommended daily intake level. The Al2O3-modified electrode exhibits excellent sensitivity towards Sunset Yellow and Tartrazine compared to a bare electrode. The effects of pH, scan rate, reproducibility, and simultaneous detection of both azo dyes were investigated using cyclic voltammetry. Interference studies for the binary Sunset Yellow and Tartrazine blend were conducted using differential pulse voltammetry. The effect of concentration was also examined separately for each dye. The maximum peak current for both dyes was observed at pH 7.0, and subsequent studies were performed at this pH. The scan rate study of SY and TZ reveals that the electrode undergoes an adsorption-controlled process. The limits of detection and quantification for Sunset Yellow were 0.103 µM and 0.346 µM, and the linear range was from 0.1 to 1.5 µM. For Tartrazine, the limits of detection and quantification were 0.705 µM and 2.352 µM, with the same linear range 1–15 µM. The prepared electrode demonstrated 73
The significant increase in the use of electronic devices resulted in an increasing amount of battery waste, especially used zinc-carbon batteries containing toxic metals and electrolytes. This situation reinforced the need for more effective recycling strategies, including the recovery of graphite and electrolyte paste for reuse as electrode materials in reverse electrodialysis systems. Reverse electrodialysis was a renewable energy technology that converted differences in salt content into electrical energy. A simple upcycling route demonstrated to converts zinc-carbon battery waste into a composite carbon electrode for reverse electrodialysis, enabling salinity-gradient energy harvesting from waste-derived materials. In this study, graphite and electrolyte paste were extracted through manual disassembly, washing, and drying, and then mixed with a polyvinyl cholride/N-methyl-2-pyrrolidone binder to create a composite electrode. Electrode characterization involved measurements of porosity, swelling degree, conductivity, and ion exchange capacity. The composition of 60
TiB2 and TiB boride layers were formed on Ti-6Al-4V using a molten-salt diffusional process at a temperature of 900 °C for 16 h. Reciprocating sliding tests in phosphate-buffered saline (PBS) solution were conducted under open circuit potential, potentiodynamic polarization (PP), and potentiostatic (+ 1 V vs. Ag/AgCl) conditions for both untreated Ti-6Al-4V and borided samples under normal loads of 0.5 N, 1 N, 5 N, and 15 N against an alumina ball. X-ray photoelectron spectroscopy (XPS) analysis revealed the presence of H3BO3/B2O3 compounds in the passive film on the borided sample under stagnant conditions, resulting in a lower breakdown potential compared with untreated Ti-6Al-4V. During the PP test under various normal loads, the corrosion current density (icorr) of Ti-6Al-4V and the borided samples increased up to 3100 and 4300 times, respectively, relative to values observed under the stagnant conditions. During sliding at a potential of + 1 V vs. Ag/AgCl, the mean corrosion current for the borided sample decreased up to 66
