Search Results (4,821)

Substantial advances have been made since the 1970s in reducing the environmental impacts of ammonia production. Renewable-driven electrochemical synthesis offers a promising pathway to decarbonize ammonia production. This review examines an integrated route in which hydrogen is generated photoelectrochemically under concentrated solar irradiation and subsequently used in electrochemical ammonia synthesis. Photoelectrochemical cells are fabricated by electrostatically depositing photosensitive particles onto cathodes to enhance light-driven hydrogen production. Hydrogen production rates and ammonia yield depend strongly on temperature and electrolyte composition. The synthesized hydrogen is fed into a molten salt electrochemical reactor that operates at atmospheric pressure and receives nitrogen from a dedicated supply. This combined solar–electrochemical approach can produce low-carbon ammonia with improved safety and reduced environmental impact, offering a scalable alternative to conventional processes. Full article

A nitrogen/sulfur co-doped reduced graphene oxide (N,S-RGO) material was rationally prepared via a modified Hummers method followed by microwave-assisted reduction. The resulting material was uniformly deposited onto a glassy carbon electrode (GCE) to fabricate an electrochemical sensor for nitrobenzene (NB) detection. The prepared N,S-RGO material was characterized in detail using Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy, confirming the successful incorporation of heteroatoms. Furthermore, electrochemical studies, including cyclic voltammetry (CV) and linear sweep voltammetry (LSV), revealed the enhanced electrical conductivity of the material. The fabricated N,S-RGO/GCE sensor exhibited remarkable electroanalytical performance, achieving a low detection limit (LOD) of 7 nM within a linear concentration range of 0.05 to 147 µM. The enhanced sensing performance is attributed to the synergistic effect of nitrogen and sulfur doping, which improves electron transfer kinetics and abundant active sites for NB reduction. Furthermore, the sensor demonstrated outstanding selectivity toward NB in the presence of common interfering substances. Its practical applicability was confirmed through the successful detection of NB in environmental water samples, yielding convincing recovery rates. These results highlight the potential of the N,S-RGO/GCE platform as an efficient and reliable electrochemical sensor for environmental monitoring of NB contamination. Full article

The development of low-cost and highly sensitive electrochemical sensing platforms for pesticide monitoring has attracted significant attention in recent years. In this study, coke-derived carbon (CDC) was successfully synthesized from petroleum coke through high-temperature carbonization under a nitrogen atmosphere. Subsequently, a CDC@CuO-NP nanocomposite was fabricated by depositing copper oxide nanoparticles onto the CDC matrix. The morphology, structure, and elemental composition of the synthesized materials were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and elemental mapping analyses, confirming the successful formation of the composite and the uniform distribution of CuO nanostructures on the carbon surface. Electrochemical characterization demonstrated that the incorporation of CuO significantly enhanced the electrochemical performance of CDC by increasing the electroactive surface area and facilitating electron transfer. The CDC@CuO-NP-modified glassy carbon electrode was applied for the electrochemical detection of dichlorvos (DDVP) using electrochemical impedance spectroscopy (EIS). The sensor exhibited a concentration-dependent increase in charge-transfer resistance and showed a linear response in the concentration range of 247–3770 nM, with the regression equation y = 47.1458C + 111.8162 and a correlation coefficient of R² = 0.9832. The developed sensor achieved a low limit of detection (LOD) of 2.3 nM, demonstrating high sensitivity toward DDVP. These results indicate that the CDC@CuO-NP nanocomposite is a promising, low-cost, and efficient electrode material for the sensitive determination of organophosphorus pesticides and has considerable potential for environmental monitoring and food safety applications. Full article

Ionic liquid-based localized high-concentration electrolytes, leveraging their intrinsically nonflammable safety characteristics and wide electrochemical windows, have emerged as strong contenders for next-generation lithium metal battery electrolytes. However, because such systems are anion-rich, the electrolyte bulk phase tends to form solvation structures dominated by bulky anionic clusters along with an excess of free anions, which triggers persistent and uncontrollable anion decomposition at the interphase. To address this issue, we adopt a strategy of constructing a compressed solvation structure by introducing a weakly interacting chlorinated diluent (TeCA), which helps form a compact solvation environment and alleviates excessive anion decomposition at electrode interphases. In this work, 1,1,2,2-tetrachloroethyl acetate (TeCA) was introduced as a weakly coordinating chlorinated diluent into an ionic-liquid localized high-concentration electrolyte (LHCE) to regulate the Li⁺-FSI⁻ solvation environment. By combining Raman spectroscopy, molecular dynamics simulations, and electrochemical characterization, the TeCA-LHCE system was found to exhibit altered ion-cluster configurations, improved oxidation tolerance, and enhanced interfacial stability under high-voltage conditions. The as-prepared TeCA-LHCE electrolyte presents improved electrochemical performance in comparison with TTE-LHCE and the baseline electrolyte (BE). The Li||Cu half-cell employing TeCA-LHCE achieved a high Coulombic efficiency above 99% over 500 cycles and formed a uniform and dense lithium deposition layer without obvious dendritic growth. When paired with a high-loading NCM811 cathode (10 mg cm⁻²), the TeCA-LHCE-based Li||NCM811 full cell delivered significantly improved cycling stability and rate capability under a high cutoff voltage of 4.3 V. Full article

The nucleation and growth mechanisms of copper electrodeposition from Cu(I)-containing-reline, a deep eutectic solvent, were investigated through a combination of electrochemical techniques and surface characterization. Cyclic voltammetry revealed the characteristic nucleation loop associated with an overpotential-driven electrocrystallization process, from which the equilibrium potential of the Cu(I)/Cu(0) redox couple was determined to be −0.35 V vs. a Ag quasi-reference electrode. Experimental potentiostatic current density transients were analyzed using nucleation models capable of accounting for both adsorption and three-dimensional (3D) diffusion-controlled growth, thereby allowing deconvolution of the individual contributions to the overall current response. The kinetic parameters, including the nucleation frequency and the number density of active sites, exhibited an exponential dependence on the applied overpotential, thus indicating enhanced nucleation kinetics at greater driving forces, while determining a Cu(I) diffusion coefficient of (3.39 + 0.09) × 10⁻⁷ cm² s⁻¹. Thermodynamic analysis showed that the Gibbs free energy of the formation of the critical nucleus decreases with increasing overpotential and follows the expected dependence on the inverse square of the overpotential, in agreement with classical nucleation theory. The estimated critical nucleus size was found to be smaller than one atom, suggesting that nucleation occurs at highly active surface sites. Furthermore, an exchange current density of (3 ± 1) μA cm⁻² was estimated for the Cu(I) electrochemical reduction. Scanning electron microscopy revealed a high density of copper nanoparticles (~20 nm) distributed across the electrode surface, along with larger aggregates (~100 nm) formed by coalescence and growth, consistent with a progressive nucleation mechanism. X-ray photoelectron spectroscopy confirmed that the deposits consist exclusively of metallic copper, with no evidence of oxidized species. These results demonstrate that copper electrodeposition in reline is governed by a complex interplay between the thermodynamic driving force, the interfacial kinetics, and mass transport, comprehensively providing fundamental insight into the electrocrystallization processes in deep eutectic solvents. Full article

Neutral salt spray tests were conducted on assemblies comprising H59 brass and either electrogalvanized or hot-dip galvanized bolts. The polarization curves, electrochemical impedance spectroscopy (EIS), corrosion morphology, elemental distribution, and corrosion product composition of the H59 brass were systematically characterized. The results demonstrated that upon coupling with galvanized bolts, the formation of a protective Cu₂O film on the H59 brass is significantly weakened, leading to accelerated corrosion. After coupling with electrogalvanized bolts, the i_corr reached a maximum value of 0.21 mA/cm². A corrosion layer predominantly composed of ZnO formed on the sample surface with a thickness of approximately 13 μm, and no penetration or enrichment of Cl was observed in the matrix. More seriously, when the brass was assembled with hot-dip galvanized bolts, the i_corr never dropped below 0.2 mA/cm². A porous and complex Zn-Cu-O-Cl mixed corrosion layer developed on its surface. This loose structure allows Cl⁻ to reach a depth of 55 μm into the matrix and continue causing corrosion. The mechanisms underlying the different corrosion behaviors of H59 brass caused by different galvanizing bolt processes require further investigation. Full article

To date, lithium–ion batteries (LIBs) are considered one of the most promising and market-leading energy storage systems due to their high theoretical capacity and energy density. However, poor thermal and cyclic stability, low electrolyte uptake, and the possibility for frequent short circuits of typical separators and evolution of several gases during long cycle operation pose several problems for LIBs. Metal-organic frameworks (MOFs) have attracted widespread interest as a promising material for improving the cycle stability and safety of rechargeable batteries due to their inherent surface and structural properties such as high specific surface area, high porosity, and ionic conductivity. In this work, the aim is to provide detailed descriptions of the synthesis routes and parameters for obtaining various MOFs such as Zr-MOF-808 and Ni-MOF-74 nanoparticles and the fabrication of those MOF-integrated separators. To optimize the crystallinity, morphological and compositional characteristics, and several material characterizations such as XRD, SEM, and EDX have been applied. Afterwards, the synthesized MOF-integrated glass fiber (GF) separators have been developed for lithium–ion battery (LIB) applications. To investigate the electrochemical performance and the effect of MOF integration into the separators, electrochemical studies in the form of galvanostatic charge–discharge (GCD), electrochemical impedance spectroscopy (EIS) have been evaluated by preparing CR2032-type half-coin cells. This MOFs-integrated GF-separators and synthesized LiNi_0.6Mn_0.2Co_0.2O₂ (NMC622) cathode materials-based coin cell LIB exhibited higher cycle stability than bare GF-separator based LIB. This novel approach and extensive research suggest that development of MOF-integrated separators could significantly improve cycle stability by reducing the internal cell degradation for next generation energy storage devices. Full article

This study presents a phenomenological estimation framework for a membraneless alkaline water electrolyzer (MAWE), developed primarily from experimentally measured current signals and end-of-test mass-loss data. Thirteen KOH concentrations (5–35 g in 1 L deionized water) were investigated under a constant 12 V DC supply for 7200 s. The time-varying current was continuously recorded throughout each experiment, while the total gas production was determined from the net mass loss measured at the end of the electrolysis process. A time-resolved hydrogen-production representation was subsequently reconstructed from the measured current signal using Faraday’s law and constrained to be stoichiometrically consistent with the experimentally observed total mass loss. The term “charge-consistent” used throughout this study does not imply a new electrochemical principle, but rather refers to maintaining physical consistency between the experimentally measured current signal, Faraday-based charge transfer, and the experimentally observed end-of-test mass loss within the proposed phenomenological framework. Experimental results indicate that both the current response and the cumulative gas production exhibit a strong and distinctly nonlinear dependence on the KOH concentration. Two phenomenological modeling approaches were examined. The first is a static polynomial formulation describing the nonlinear relationship between the measured current signal and the reconstructed production rate. The second is a semi-empirical grey-box formulation in which the Faraday-based theoretical production term is corrected using an experimentally identified efficiency coefficient. Model performance was assessed using train/test data partitioning, residual analysis, autocorrelation functions, and Ljung–Box tests, demonstrating a high degree of internal charge consistency and macroscopic agreement with the reconstructed experimental representation. The proposed framework provides a reduced-order and experimentally accessible approach for representing reconstructed production behavior in MAWE systems without resorting to detailed multi-physics modeling or EIS-based characterization and offers a physically consistent baseline for comparison with more complex data-driven or control-oriented modeling strategies. Full article

Binder-free NiMn₂O₄@NiCo₂O₄ nanocomposites with NiMn₂O₄ nanoparticle (NP) surface coverage on NiCo₂O₄ nanosheets (NSs) are fabricated on nickel foam (NF) via a two-step microwave-assisted hydrothermal (MAH) method combined with annealing treatment, which can be used as a high-performance electrode material for supercapacitors. Specifically, a tulle-like NiCo₂O₄ nanosheet framework is first in situ grown on NF, followed by the growth of NiMn₂O₄ NPs on the surface of NiCo₂O₄ NSs via a secondary MAH process. To investigate the effect of the second-step holding time (HT) of MAH on material performance, a series of experiments were carried out with an HT of 15, 30, 45, and 60 min, and the microstructures and electrochemical properties of the products were analyzed. Structural characterization results confirm the successful synthesis of well-defined NiMn₂O₄-NPs@NiCo₂O₄-NSs composites. Electrochemical tests demonstrate that the product at an HT of 30 min has the best electrochemical performance with a higher specific capacitance of 441.56 F·cm⁻² at 1 A·cm⁻² and cycling stability (75% capacitance retention after 5000 cycles at 15 A·cm⁻²). The superior electrochemical properties are mainly attributed to the unique porous tulle-like NS structure with the largest specific surface area of the 30 min product. This distinctive structure affords abundant electrochemical active sites, effectively prevents structural collapse during long-term cycling, and shortens the transmission and diffusion pathways of electrons and electrolyte ions. The optimized NiMn₂O₄@NiCo₂O₄ electrode material presents extensive application prospects for high-performance supercapacitors. Full article

Surface engineering strongly influences the performance, reliability, and safety of medical and biomedical devices, yet failures often originate at interfaces rather than in bulk materials alone. This review addresses the fragmented evidence base linking coating selection, interphase design, qualification testing, advanced characterization, and data-driven durability analysis. The objective is to provide an integrative, failure-mode-based framework for implants, reusable instruments, inhalation systems, diagnostics, wearables, and implantable electronics. A narrative synthesis of the peer-reviewed literature in coatings, biomaterials, electrochemistry, reliability, standards, and materials informatics was conducted, with qualitative tables used only when protocols were too heterogeneous for numerical pooling. The review compares physical vapor deposition (PVD), chemical and plasma-enhanced chemical vapor deposition (CVD/PECVD), atomic layer deposition (ALD), sol–gel/organically modified silica (ORMOSIL) hybrids, plasma polymers, parylene, bioactive or antimicrobial surfaces, and electronic encapsulation strategies. The main finding is that no universally superior coating exists; reliable performance depends on matching architecture and characterization to the dominant failure pathway, substrate compliance, geometry, sterilization or physiologic exposure, and the standards-constrained endpoint. The review further shows how electrochemical diagnostics, interfacial mechanics, multiphysics models, survival/reliability statistics, and carefully governed AI workflows can be combined to support service-life prediction and decision-oriented qualification. Full article

Lithium-ion batteries with high energy density and long cycle life have been widely used as secondary batteries in electric vehicles and energy storage systems. With the growing demand for high energy density in lithium-ion batteries, silicon-based materials, which possess a high theoretical specific capacity (4200 mAh g⁻¹), are regarded as core candidates for anode materials. However, Si-based materials undergo severe volume expansion (up to 300%), which leads to the collapse of the electrode structure, inducing pulverization of the active material and capacity loss, thereby hindering the commercial application of silicon-based materials. To address these issues, scholars from various countries have developed many silicon-based materials with different compositions and three-dimensional structures, and have made some research progress. This review first elaborates on the lithium storage mechanisms and advantages of diverse silicon-based anode materials by taking Si, SiO_x, SiN_x, and SiP_x as representative examples with distinct characteristics. Subsequently, from the two aspects of dimensional design (0D, 1D, 2D and 3D) and architecture design (core–shell, sandwich-like and network structure), the design strategies for various silicon-based anode structures and their enhancement on electrochemical performance are analyzed. Finally, this review elucidated the challenges faced by silicon-based anodes from the perspectives of mechanism elucidation, structural customization, industrialization, and full-cell applications. It also proposed future development directions for silicon anodes by combining actual challenges and focusing on aspects such as structure optimization, machine learning, advanced characterization techniques, and mechanistic analysis. Full article

Lithium-ion batteries (LIBs) are subject to mechanical abuse both in electric vehicles and consumer electronic applications when dropped, which can lead to capacity degradation even if the cells survive the impact. This study investigates the impact of mechanical damage on the electrochemical performance of LIBs, focusing on capacity retention and internal resistance changes. The batteries were subjected to dynamic mechanical impact using varying impact energies (3J, 5J, and 7J) while measuring internal resistance and capacity before and after the impact. Hybrid Pulse Power Characterization (HPPC) was employed to assess internal resistance and capacity degradation across multiple cycles. Our results demonstrate that even minor mechanical damage can cause significant performance decay, especially after several cycles. The study also reveals that the state of charge (SOC) prior to impact has a minimal effect on the survival rate of the cells but influences the extent of damage observed. Post-impact analysis using optical microscopy indicates structural damage, including separator tears and delamination, contributing to capacity fade. This work highlights the importance of considering intermediate mechanical damage in LIB safety and performance assessments. Full article

Monometallic nanoparticles tend to aggregate and exhibit limited catalytic performance, rendering them inadequate for high-efficiency electrocatalytic applications. In this study, a green and mild liquid-phase reduction method was employed, using sodium borohydride to simultaneously reduce graphene oxide (GO) and metal precursors. This approach enabled the uniform and highly dispersed loading of silver–copper bimetallic alloy nanoparticles (Ag_1−xCu_x NPs) onto the surface of reduced graphene oxide (RGO). By tuning the Ag/Cu molar ratio, the size, composition, and morphology of the nanoparticles were precisely controlled. Characterization by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) confirmed that GO was efficiently reduced to RGO, and the bimetallic nanoparticles were uniformly distributed on the RGO surface in an alloy state with small particle size and no obvious agglomeration. A strong interfacial interaction between the metal nanoparticles and the support was also observed. Electrochemical tests demonstrated that the composite exhibits excellent electrocatalytic activity toward the reduction of H₂O₂. Notably, the reduction peak current at the Ag_0.5Cu_0.5NPs/RGO modified electrode was 1.8 and 2.3 times higher than those at the monometallic Ag/RGO and Cu/RGO electrodes, respectively. These results provide a reliable theoretical basis and a viable research route for the controllable synthesis of low-cost, high-performance electrocatalytic nanocomposites and their application in electrochemical H₂O₂ sensing. Full article

A pyranochromene-based ligand, 2-amino-4-(4-chlorophenyl)-5-oxo-4H,5H-pyrano[3,2-c]chromene-3-carbonitrile (ACLPh-PC-3-CN), was employed as a chelating modifier for the electrochemical determination of Cd(II) in water samples. ACLPh-PC-3-CN was co-immobilized with Nafion on a glassy carbon electrode to form a stable ACLPh-PC-3-CN/Nafion film that combines ligand-based coordination with cation-exchange-assisted preconcentration of Cd²⁺ at the electrode surface. The Cd(II) response at the modified electrode was characterized by cyclic voltammetry and differential pulse anodic stripping voltammetry, and the data support a predominantly 1:1 Cd(II)–ligand interaction at the interface under the selected conditions. At an optimized pH of 6.0, the sensor provided a linear calibration range from 16.21 to 56.72 μM, with a detection limit of 0.60 μM and a quantification limit of 2.0 μM, and showed good precision (repeatability 2.3% RSD, reproducibility 3.1% RSD) and short-term stability (94% of the initial response after 14 days). The ACLPh-PC-3-CN/Nafion-modified electrode tolerated common inorganic ions and surfactant species (≤5% signal change) and was successfully applied to the determination of Cd(II) in tap water and Red Sea water, affording recoveries between 98.7% and 101%. While the current detection limit is higher than typical guideline values for Cd in drinking water, the proposed sensor compares favorably with several reported electrochemical Cd(II) sensors in terms of simplicity, precision, and matrix tolerance, and represents a useful platform for coordination-based electrochemical sensing of cadmium in environmental water samples. Full article

This study was conducted to explore how varying the concentration of nano-La₂O₃ particles in the plating bath influences the morphology, constitution, and corrosion resistance of Ni-B composite coatings deposited on N80 carbon steel via electroless plating. The novelty of this work lies in the systematic investigation on the co-deposition behavior and grain refinement mechanism of nano-La₂O₃ in electroless Ni-B system, which has been rarely reported in previous studies. The microstructure and chemical composition of the coatings were characterized through a combination of SEM, EDS, XPS and XRD analyses. SEM confirmed that a dense Ni-B/La₂O₃ composite coating was formed, with a uniform thickness of approximately 10 μm, and the nano-La₂O₃ particles were evenly distributed. XPS analysis verified the presence of B, C, O, Ni and La, while XRD analysis revealed a refinement in crystalline size due to the addition of the nanoparticles. The corrosion resistance enhancement mechanism is attributed to the triple synergistic effect: nano-La₂O₃ pins grain boundaries and refines Ni-B grains to the minimum average size of 12.943 nm at the optimal concentration of 8 g·L⁻¹; the refined grain structure promotes the formation of a continuous and dense Ni(OH)₂ passive film; the uniformly dispersed nanoparticles act as physical barriers to block the penetration of corrosive media. Electrochemical measurements demonstrated that this coating exhibited outstanding anti-corrosion performance, as confirmed by a remarkably positive corrosion potential (E_corr = −0.37189 V) and a minimal corrosion current density (I_corr = 3.7524 μA/cm²). The results conclusively show that nano-La₂O₃ reinforcement effectively enhances the corrosion protection performance of electroless Ni-B alloy coatings. Full article