Search Results (136)

The electrochemical conversion of CO₂ into high-purity Graphene NanoCarbon (GNC) materials provides a compelling path to address climate change while producing economically valuable nanomaterials. This work presents the progress and prospects of new large-scale syntheses of GNC allotropes via the C2CNT (CO₂ to Carbon Nano Technology) process. The C2CNT molten carbonate electrolysis technique enables the formation of Carbon NanoTubes (CNTs), Magnetic CNTs (MCNTs), Carbon Nano-Onions (CNOs), Carbon Nano-Scaffolds (CNSs), and Helical CNTs (HCNTs) directly from atmospheric or industrial CO₂. We discuss the morphology control enabled through variations in electrolyte composition, temperature, current density, and nucleation additives. We present results from scaled operations reaching up to 1000 tons/year CO₂ conversion and propose design approaches to reach megaton scales to support climate mitigation and GNC mass production. The products demonstrate high crystallinity, as evidenced by Raman, XRD, SEM, and TGA analyses, and offer promising applications in electronics, construction, catalysis, and medical sectors. Full article

Lithium–sulfur (Li-S) batteries are hindered by the sluggish electrochemical kinetics and poor reversibility of lithium polysulfides (LiPSs), which limits their practical energy density and cycle life. In order to address this issue, a novel Ni₃N/Nb₄N₅ heterostructure was synthesized via electrospinning and nitridation as a functional coating for polypropylene (PP) separators. Adsorption experiments were conducted in order to ascertain the heterostructure’s superior affinity for LiPSs, thereby effectively mitigating their shuttling. Studies of Li₂S nucleation demonstrated the catalytic role of the substance in accelerating the deposition kinetics of Li₂S. Consequently, Li-S cells that employed the Ni₃N/Nb₄N₅-modified separator were found to achieve significantly enhanced electrochemical performance, with the cells delivering an initial discharge capacity of 1294.4 mAh g⁻¹ at 0.2 C. The results demonstrate that, after 150 cycles, the cells retained a discharge capacity of 796.2 mAh g⁻¹, corresponding to a low capacity decay rate of only 0.25% per cycle. In addition, the rate capability of the cells was found to be improved in comparison to control cells with NiNb₂O₆-modified or pristine separators. Full article

This study synthesized two eco-friendly inhibitors—a chitosan–copper metal–organic framework (CS@Cu MOF) and chitosan–Schiff base–Cu complex (Schiff–CS@Cu)—for Q345 steel protection in 3.5% NaCl/1M HCl. Electrochemical and weight loss analyses demonstrated exceptional corrosion inhibition: untreated specimens showed a 25.889 g/(m²·h) corrosion rate, while 100 mg/L of CS@Cu MOF and Schiff–CS@Cu reduced rates to 2.50 g/(m²·h) (90.34% efficiency) and 1.67 g/(m²·h) (93.56%), respectively. Schiff–CS@Cu’s superiority stemmed from its pyridine–Cu²⁺ chelation forming a dense coordination barrier that impeded Cl⁻/H⁺ penetration, whereas CS@Cu MOF relied on physical adsorption and micro-galvanic interactions. Surface characterization revealed that Schiff–CS@Cu suppressed pitting nucleation through chemical coordination, contrasting with CS@Cu MOF’s porous film delaying uniform corrosion. Both inhibitors achieved optimal performance at 100 mg/L concentration. This work establishes a molecular design strategy for green inhibitors, combining metal–organic coordination chemistry with biopolymer modification, offering practical solutions for marine infrastructure and acid-processing equipment protection. Full article

Electroless nickel deposition (ELD) on polymer substrates enables the fabrication of flexible, conductive fibres for wearable and functional textiles. However, achieving uniform, low-defect coatings on synthetic fibres such as nylon-6,6 remains challenging due to their chemical inertness, hydrophobicity, and poor interfacial compatibility with metal coatings. This study presents a solvent-assisted approach using dimethyl sulfoxide (DMSO) in a conventional aqueous ELD bath to control both polymer–metal interfacial chemistry and nickel coating microstructure. The modified surface supports dense catalytic sites, triggering spatially uniform Ni nucleation. The combination of scanning electron microscopy and transmission electron microscopy confirms the difference in coarse grains with fully aqueous baths to a nanocrystalline shell with DMSO-modified baths. This refined microstructure relieves residual stress and anchors firmly to the swollen polymer, delivering +7 °C higher onset decomposition temperature and 45% lower creep strain at 50 °C compared with aqueous controls. The fabric strain sensor fabricated by 1 wt.% DMSO-modified ELD shows a remarkable sensitivity against strain, demonstrating a 1400% resistance change under 200% stain. Electrochemical impedance and polarisation tests confirm a two-fold rise in charge transfer resistance and negligible corrosion current drift after accelerated ageing. By clarifying how a polar aprotic co-solvent couples polymer swelling with metal growth kinetics, the study introduces a scalable strategy for tuning polymer–metal interfaces and advances solvent-assisted ELD as a route to mechanically robust, thermally stable, and corrosion-resistant conductive textiles. Full article

The novel pyridine oxime-based complexing agents 2-pyridinecarboxaldehyde oxime, 2-acetylpyridine ketoxime and 2-pyridine amidoxime were synthesized for alkaline Zn-Ni alloy electrodeposition, outperforming conventional citrate/TEPA systems in corrosion resistance and microstructural control. The N,O-bidentate chelation mechanism governs metal ion reduction kinetics via diffusion-limited pathways, enabling γ-phase Ni₅Zn₂₁ intermetallic formation and nanocrystalline refinement. Electrochemical and microstructural analyses demonstrate suppressed random nucleation and hydrogen evolution side reactions, leading to enhanced charge transfer resistance and reduced corrosion current density. Notably, 2-pyridine amidoxime achieves ultrasmooth surfaces through defect-free nanocluster growth, while 2-pyridinecarboxaldehyde oxime maximizes γ-phase crystallinity. The synergy between grain boundary density and surface integrity establishes a dual protection mechanism combining barrier layer formation and active dissolution suppression. This work advances microstructure engineering via coordination chemistry, offering a breakthrough over traditional zincate electroplating for high-performance anti-corrosion coatings. Full article

The mixture powders were designed by adding 0 wt.%~1.0 wt.% CeO₂ into the 2205 duplex stainless steel (DSS) powders. The 2205 DSS cladding layer was prepared on the surface of Q345 steel by plasma arc cladding technology. The effects of different CeO₂ contents on the macro-morphology, microstructure composition, and corrosion resistance of the cladding layer were studied. The action mechanism of CeO₂ in the cladding layer was also discussed. The results showed that the addition of CeO₂ modified the appearance and decreased the defect of the cladding layer. Also, the austenite grains were refined, and the austenite proportion was increased under the action of CeO₂. When the CeO₂ content was 0.5 wt.%, the appearance of the cladding layer was optimum; the austenite proportion in the upper cladding layer and the lower cladding layer reached up to 52.6% and 55.5%, respectively, and the crystal changed from columnar to equiaxed. CeO₂ decomposes into Ce element and O element under the action of the plasma arc, after which Ce element is easily absorbed at the grain boundary to reduce the surface tension and improve the fluidity of the liquid metal so as to modify the appearance of the cladding layer. Meanwhile, Ce element primarily reacts with O, S, Al, and Si elements to form low-melting-point oxygen sulfides and are then removed, which eliminates the defect of the cladding layer. Moreover, the high melting point of CeO₂ acts as heterogeneous nucleation sites during solidification, thus improving the value of nucleation rate/growth rate of the grain and promoting the transformation from ferrite to austenite. According to the electrochemical corrosion testing result, Ce element inhibited the enrichment of Cr element at grain boundaries and promoted the formation of Cr₂O₃, which improved the corrosion resistance of the 2205 DSS cladding layer. It was optimum with the CeO₂ content of 0.5 wt.%. Full article

Metallic lithium anodes possess the lowest redox potential (−3.04 V vs. SHE) and an ultra-high theoretical capacity (3860 mAh g⁻¹, 2061 mAh cm⁻³). However, during electrochemical cycling, lithium metal tends to plate unevenly, leading to the formation of lithium dendrites. Moreover, severe electrochemical corrosion occurs at the interface between metallic lithium and traditional copper foil current collectors. To address these issues, we selected corrosion-resistant carbon paper as a lithium metal host and modified a uniform distribution of silver nanoparticles and a F-doped amorphous carbon structure as a highly lithiophilic F-CP@Ag host to enhance lithium-ion transport kinetics and achieve improved affinity with lithium metal. The silver nanoparticles reduced the lithium nucleation energy barrier, while F doping resulted in a LiF-rich solid electrolyte interphase that better accommodated volume changes in lithium metal. These two strategies worked together to ensure uniform and stable lithium metal plating/stripping on the F-CP@Ag host. Consequently, under the conditions of 1 mA cm⁻² and 1 mAh cm⁻², the symmetric cell exhibited stable cycling with a polarization voltage of 8 mV for up to 1400 h. This work highlights the corrosion problem of lithium metal on traditional copper foil current collectors and provides guidance for the long-term cycling stability of lithium metal anodes. Full article

Uneven local electric fields and limited nucleation sites at the reaction interface can lead to the formation of hazardous lithium (Li) dendrites, posing a significant safety risk and impeding the practical utilization of Li metal anodes (LMAs). Here, we present a method utilizing atomic layer deposition (ALD) to create lithiophilic titanium nitride (TiN) sites on carbon nanotubes (CNTs) surfaces, integrated with nanocellulose to form a lithiophilic interlayer (NFCP@TN). This interlayer, which is highly flexible and electrolyte-wettable, functions as a current collector and host material for LMAs. The uniform deposition of Li is facilitated by the synergistic interplay of the lithiophilic active sites TiN, the conductive CNT network, and excellent electrolyte wettability of nanocellulose. As a result, Li preferentially adsorbs on TiN sheaths with lower diffusion barriers, leading to controlled nucleation sites and dendrite-free Li deposition. Furthermore, the well-designed NFCP@TN interlayer exhibits exceptional electrochemical performance and significantly extended cycle life when paired LMA with high areal capacity NCM811 (5.0 mAh cm⁻²) electrodes. Full article

Titanium oxynitride (TiNO) thin films represent a multifaceted material system applicable in diverse fields, including energy storage, solar cells, sensors, protective coatings, and electrocatalysis. This study reports the synthesis of TiNO thin films grown at different substrate temperatures using pulsed laser deposition. A comprehensive structural investigation was conducted by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Non-Rutherford backscattering spectrometry (N-RBS), and X-ray absorption spectroscopy (XAS), which facilitated a detailed analysis that determined the phase, composition, and crystallinity of the films. Structural control was achieved via temperature-dependent oxygen in-diffusion, nitrogen out-diffusion, and the nucleation growth process related to adatom mobility. The XPS analysis indicates that the TiNO films consist of heterogeneous mixtures of TiN, TiNO, and TiO₂ phases with temperature-dependent relative abundances. The correlation between the structure and electrochemical behavior of the thin films was examined. The TiNO films with relatively higher N/O ratio, meaning less oxidized, were more electrochemically active than the films with lower N/O ratio, i.e., more oxidized films. Films with higher oxidation levels demonstrated enhanced crystallinity and greater stability under electrochemical polarization. These findings demonstrate the importance of substrate temperature control in tailoring the properties of TiNO film, which is a fundamental part of designing and optimizing an efficient electrode material. Full article

Green hydrogen, produced via electrolysis using renewable energy, is a zero-emission fuel essential for the global transition to sustainable energy systems. Optimizing hydrogen production requires a detailed understanding of bubble dynamics at the cathode, which involves three key stages: nucleation, growth, and detachment. In this study, hydrogen bubble growth was investigated in a custom-built electrolysis cell with microelectrodes, combining high-speed imaging and electrochemical measurements with a potentiostat. The results reveal distinct growth regimes governed by a potential-dependent time exponent, captured through a power law. Within the evaluated range of potentials, three regions with different bubble departure behaviors were identified: (i) at low potentials (2.0–2.6 V), bubbles depart without coalescing, (ii) in the transitional region (2.6–3.2 V), bubbles coalesce to varying degrees before detachment, and (iii) at high potentials (≥3.2 V), large, coalesced bubbles dominate. These findings highlight the significant impact of coalescence on bubble growth and departure behavior, affecting electrode coverage with gas and, consequently, electrolysis efficiency. Understanding these interactions is crucial for improving hydrogen evolution efficiency by mitigating bubble-induced mass transport limitations. The findings contribute to advancing electrolysis performance, offering insights into optimizing operating conditions for enhanced hydrogen production. Full article

Considering the various morphologies of carbon nanotubes (CNTs), it is expected to solve the contradiction between concentration polarization and electrochemical polarization in vanadium redox flow batteries (VRFBs). This paper investigates the structural evolution of CNTs grown on the surface of thermally oxidized carbon cloth (TCC) and their impact on the performance of VRFBs. The morphological results indicate that thermal oxidation treatment forms pores on the surface of the TCC, providing nucleation sites for CNT growth. Spiral-shaped CNTs (TCC@s-CNTs) were formed in a short growth time (1 h), and their high defect density originated from the non-steady-state supply of carbon sources and the dynamic behavior of the catalyst. While 3 h of growth forms a network structure (TCC@n-CNT), the van der Waals force drives the self-assembly of its three-dimensional network. Although the TCC@s-CNT exhibits high catalytic activity due to its high defect density and edge active sites, the performance of VRFBs is more dependent on the three-dimensional conductive network of the TCC@n-CNT. At 240 mA/cm², the energy efficiency (EE) of a VRFB assembled with the TCC@n-CNT reaches 71%, and the capacity retention rate is 15% higher than that of the TCC@s-CNT. This work reveals the synergistic mechanism of CNT morphology regulation on electrode performance and provides theoretical guidance for the design of VRFB electrodes. Full article

Mechanical properties and corrosion resistance of La₂O₃/A356 composites with different contents of La₂O₃ were investigated by optical microscopy, X-ray diffractometry, scanning electron microscopy, electrochemical tests, and immersion corrosion tests. The results show that the addition of La₂O₃ refined the α-Al phase of the A356 matrix, and the long stripe-like Si phase and β-Al₅FeSi phase were transformed into short rod-like forms. The La₂O₃/A356 composites with 1.0 wt.% La₂O₃ exhibited the most optimal mechanical properties and corrosion resistance. The yield strength, ultimate tensile strength, and elongation of La₂O₃/A356 composites with 1.0 wt.% La₂O₃ were higher than those of the matrix. The results of electrochemical experiments and the immersion corrosion test show that the corrosion potential of La₂O₃/A356 composites with 1.0 wt.% La₂O₃ was 72 mV higher than that of the matrix, the corrosion current density was 84.8% lower than that of the matrix, and the impedance Z was improved by 59.1% compared to the matrix. The addition of La₂O₃ improved the mechanical properties of the A356 matrix by refining the grains, inhibiting the nucleation of eutectic Si, and promoting the twinning growth mechanism. Moreover, the effect of La₂O₃ on the micro-galvanic corrosion behavior of A356 was discussed. Full article

Laser conversion of commercial polymers to laser-induced graphene (LIG) using inexpensive and accessible CO₂ lasers has enabled the rapid prototyping of promising electronic and electrochemical devices. Frequently used to pattern interdigitated supercapacitors, few approaches have been developed to pattern batteries—in particular, full cells. Herein, we report an LIG-based approach to a planar, interdigitated Li-S battery. We show that sulfur can be deposited by selective nucleation and growth on the LIG cathode fingers in a supersaturated sulfur solution. Melt imbibition then leads to loadings as high as 3.9 mg/cm² and 75 wt% sulfur. Lithium metal anodes are electrodeposited onto the LIG anode fingers by a silver-seeded, pulse-reverse-pulse method that enables loadings up to 10.5 mAh/cm² to be deposited without short-circuiting the interdigitated structure. The resulting binder/separator-free flexible battery achieves a capacity of over 1 mAh/cm² and an energy density of 200 mWh/cm³. Unfortunately, due to the use of near stoichiometric lithium, the cycle-life is sensitive to lithium degradation. While future work will be necessary to make this a practical, flexible battery, the interdigitated structure is well-suited to future operando and ex situ studies of Li-S and related battery chemistries. Full article

Optical microscope (OM), energy dispersive spectrometer (EDS), electron backscatter diffractometer (EBSD), electrochemical test, and transmission electron microscope (TEM) were employed to conduct interface microstructure observation and cladding corrosion resistance analysis on 304 SS/CS clad plates that have four different reduction ratios. The increase in rolling reduction ratio leads to larger grain size, gradually refined microstructure, and a decreased thickness of the interfacial martensite area. As the concentration disparity of the C element between carbon steel (CS) and 304 stainless steel (SS) is small, no evident carburization layer or decarburization layer can be detected. The ferrite microstructure on the CS side has greater stress distribution and greater local orientation deviation, and deformed grains are dominant. Austenite undergoes strain-induced martensitic transformation with the transformation mechanism of γ→twinning→a’-martensite. The martensite microstructure within the interface region grows in the direction of the interior of austenite grains. The reduction ratio increases sharply, leading to an increase in dislocation density, which promotes the nucleation, growth, and precipitation of carbides and seriously reduces the corrosion resistance of the cladding. Subsequently, the reduction ratio keeps on increasing. However, the degree of change in the reduction ratio diminishes. High temperature promotes the dissolution of carbides and improves the corrosion resistance. From this, it can be understood that by applying the process conditions of raising the reduction ratio and keeping a high temperature at the carbide dissolution temperature, a clad plate that has excellent interface bonding and remarkable corrosion resistance can be acquired. Full article

This article addresses the knowledge gap regarding the effect of Ti addition on the microstructure and corrosion behavior of the LMD-processed GH3536 alloy in a simulated solution of proton exchange membrane fuel cells (PEMFCs). The microstructural evolution, corrosion resistance, and passive film characteristics of LMD-processed GH3536 alloy with varying Ti contents were characterized through a variety of techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), electron backscatter diffraction (EBSD), X-ray photoelectron spectroscopy (XPS), and a series of electrochemical measurements. The results indicate that the corrosion resistance of the LMD-processed GH3536 alloy significantly improves with increasing Ti content. However, when the Ti content exceeds 0.2 wt.%, the beneficial effect on corrosion resistance is weakened. Two primary mechanisms explain the enhanced corrosion resistance, involving the heterogeneous nucleation of Ti-modified Al₂O₃ and Ti solute segregation, which promotes grain refinement. In addition, grain refinement can provide more active sites for the formation of compact passive films, thereby improving corrosion resistance of the GH3536 alloy. Full article