Search Results (668)

Pipeline steels under cyclic loading in corrosive environments are prone to wear and corrosion–wear synergy. Low-dilution, high-reliability Ni-based Cold Metal Transfer (CMT) overlays are therefore required to ensure structural integrity. In this work, three overlay architectures were deposited on L415QS pipeline steel: a single-layer ERNiFeCr-1 coating, a double-layer ERNiFeCr-1/ERNiFeCr-1 coating, and an ERNiCrMo-3 interlayer plus ERNiFeCr-1 working layer. The microstructure, interfacial composition gradients, and dry sliding wear behavior were systematically characterized to clarify the role of interlayer design. The single-layer ERNiFeCr-1 coating shows a graded transition from epitaxial columnar grains to cellular/dendritic and fine equiaxed grains, with smooth Fe dilution, Ni–Cr enrichment, and a high fraction of high-angle grain boundaries, resulting in sound metallurgical bonding and good crack resistance. The double-layer ERNiFeCr-1 coating contains coarse, strongly textured columnar grains and pronounced interdendritic segregation in the upper layer, which promotes adhesive fatigue and brittle spalling and degrades wear resistance and friction stability. The ERNiCrMo-3 interlayer introduces continuous Fe-decreasing and Ni-Cr/Mo-increasing gradients, refines grains, suppresses continuous brittle phases, and generates dispersed second phases that assist crack deflection and load redistribution. Under dry sliding, the tribological performance ranks as follows: interlayer + overlay > single-layer > double-layer. The ERNiCrMo-3 interlayer system maintains the lowest and most stable friction coefficient due to the formation of a dense tribo-oxidative glaze layer. These results demonstrate an effective hierarchical alloy-process design strategy for optimizing Ni-based CMT overlays on pipeline steels. Full article

In this study, thin molybdenum nitride (MoN_x) layers were directly synthesized on molybdenum foil via thermal treatment under an NH₃ atmosphere, and their phase evolution, structural characteristics, and electrochemical performance were investigated. The thickness and morphology of the MoN_x layers were controlled by varying ammonolysis time and temperature, while subsequent annealing in N₂ converted the nitride layer into MoO₂. Meanwhile, oxidation in air yielded crystalline MoO₃ layers. X-ray diffraction and X-ray photoelectron spectroscopy confirmed progressive oxidation of molybdenum, with Mo 3d binding energies increasing in the sequence of Mo < MoN_x < MoO₂ < MoO₃, consistent with their nominal oxidation states. Electrochemical characterization revealed that both MoN_x/Mo and MoO₂/Mo electrodes exhibit notable pseudocapacitive behavior in 0.5 M H₂SO₄ electrolyte, with areal specific capacitances reaching up to 520 mF cm⁻² at 10 mV s⁻¹. Increasing layer thickness led to enhanced capacitance, likely due to an increase in the electrochemically accessible surface area and the extension of ion diffusion pathways. MoO₂-coated samples showed stronger faradaic contribution and superior rate capability compared to MoN_x counterparts, along with a gradual shift from predominantly electric double-layer capacitance toward hybrid pseudocapacitive charge storage mechanisms. Full article

Tungsten oxide (WO₃) nanostructures have emerged as promising electroactive materials due to their high pseudocapacitance, structural versatility, and chemical stability, while reduced graphene oxide (rGO) provides excellent electrical conductivity and surface area. The strategic combination of these nanomaterials in hybrid electrodes has gained attention for enhancing the energy storage performance of supercapacitors. In this work, we report the fabrication and electrochemical performance of nanostructured multilayer films based on the electrostatic Layer-by-Layer (LbL) self-assembly of poly (amidoamine) (PAMAM) dendrimers alternated with tungsten oxide (WO₃) nanofibers dispersed in reduced graphene oxide (rGO). The films were deposited onto indium tin oxide (ITO) substrates and subsequently subjected to electrochemical reduction. UV-Vis spectroscopy confirmed the linear growth of the multilayers, while atomic force microscopy (AFM) revealed homogeneous surface morphology and thickness control. Electrochemical characterization by cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) revealed a predominantly electrical double-layer capacitive (EDLC) behavior. From the GCD measurements (PAMAM/rGO-WO₃)₂₀ films achieved an areal capacitance of ≈2.20 mF·cm⁻², delivering an areal energy density of ≈0.17 µWh·cm⁻² and an areal power density of ≈2.10 µW·cm⁻², demonstrating efficient charge storage in an ultrathin electrode architecture. These results show that the synergistic integration of PAMAM dendrimers, reduced graphene oxide, and WO₃ nanofibers yields a promising strategy for designing high-performance electrode materials for next-generation supercapacitors. Full article

Background: Wound healing is a typical biological process that the human body accomplishes through well-defined stages. The complexity of the healing process continues to be a significant health challenge. Multifunctional polymeric bilayer wound dressings have emerged as a new treatment option, as they resemble the bilayer structure of skin. Methods: Here, we developed a bilayer film with two distinct features, i.e., a primary sodium alginate (Na-Alg)-based sustained release layer incorporated with bergamot essential oil (BEO) and a secondary immediate release layer of hydroxypropyl methyl cellulose (HPMC) and hydroxyethyl cellulose (HEC) loaded with the antibacterial drug ofloxacin (OFX). Using the double solvent casting technique. Results: The resultant bilayer films exhibited good folding endurance and swelling capability. The antibacterial potential was appraised by assessing their capability to hinder the growth of S. aureus (40 mm zone of inhibition) and E. coli (46 mm zone of inhibition). A DPPH assay confirmed the anti-oxidant ability of the incorporated essential oil. The outcomes of the X-ray diffraction and FTIR analysis support the even and complete dispersion of the oil and drug into the polymeric matrix without any unwanted interaction. The SEM results revealed a slightly microstructured surface view, while microporous structures were discovered in the cross-section due to the presence of the oil and drug. In the in vivo wound model, the developed bilayer films demonstrated a quicker rate of wound closure (98.5% in 12 days) and avoided wound infection. Histological studies verified that the created dressing enhanced the deposition of mature collagen and promoted epithelialization. Conclusions: As a result, the unique blend of anti-inflammatory and antibacterial properties in bilayer films can significantly offer fresh perspectives for developing sophisticated, multipurpose wound dressings to hasten the healing of cutaneous wounds. Full article

This study introduces a modified Laser Ablation Synthesis in Solution (LASiS), a surfactant-free and rapid synthesis approach that enables uniform MOF nucleation on graphene oxide (GO) and precise control over crystallinity, for fabricating graphene oxide (GO)-integrated cobalt-based ZIF-67 hybrid nanocomposites tailored for supercapacitor applications. By tuning LASiS parameters, we precisely controlled framework size, morphology, and crystallinity, enabling sustainable and scalable production. The incorporation of GO during synthesis markedly enhances the uniform dispersion of ZIF-67 frameworks, minimizing aggregation and establishing interconnected conductive pathways via strong $\pi$-$\pi$ stacking interactions. Following thermal reduction at 250 °C, the Co/ZIF-67–rGO composites exhibit outstanding electrochemical performance, achieving a specific capacitance of 1152 Fg⁻¹ at 1 Ag⁻¹ in a three-electrode configuration, driven by the synergistic combination of pseudocapacitive cobalt centers and double-layer capacitance from rGO. Structural analyses confirm the preservation of ZIF crystallinity and robust interfacial integration with the graphene sheets. Embedding these nanocomposites into fully 3D-printed supercapacitors yields a specific capacitance of 875 Fg⁻¹, demonstrating their suitability for additive manufacturing despite minor increases in interfacial resistance. The 3D-printed supercapacitor devices delivered an energy density of 77.7 Wh/kg at a power density of 399.6 W/kg. Collectively, these results highlight the potential of LASiS-engineered MOF-based nanocomposites as scalable, high-performance materials for next-generation energy storage devices. Full article

Nowadays, the development of efficient water treatment processes is increasingly driven by the need to provide solutions for contaminants of emerging concern. Electrochemical advanced oxidation processes (EAOPs) based on diamond electrodes can be part of innovative removal concepts. However, expensive substrates, energy-intensive chemical vapor deposition (CVD) of diamond, and market availability complicate matters for diamond electrodes to gain traction in the water treatment sector. In addition, it has to be stated that the mining and complex processing of necessary substrates like Si, Ti, Nb, or Ta need a significant amount of fresh water, which counteracts the need for more sustainability in the field of EAOPs. In this context, a ceramic-based boron-doped diamond (BDD) electrode is presented, which addresses this dilemma. The presented concept of the so-called interdigitated double diamond electrode (iDDE) consumes 14–46% less energy in batch-mode experiments to degrade an organic model molecule compared to standard BDD technology in a poorly conductive electrolyte (κ < 350 µS/cm). Laser-induced micro-structuring of the BDD layer reduces the interelectrode spacing (IES) of the iDDE to below 50 µm. The structuring approach at the micrometer scale enables the treatment of electrically low-conductivity electrolytes more energy efficiently, while reducing the need for a supporting electrolyte or a proton exchange membrane. Degradation experiments and Raman measurements reveal different properties of an iDDE compared to standard BDD technology. The iDDE concept highlights the need to understand the significance of non-uniform current density distributions on the general electrochemical activity of BDD electrodes. Full article

Based on a realistic three-dimensional geometric model, this study numerically investigates the influence of yttria-stabilized zirconia (YSZ) thermal barrier coatings (TBCs) on the aerothermal performance of an annular combustor by employing a conjugate heat transfer (CHT) and non-premixed reactive flow coupling approach. Considering the inner and outer liners, double-wall exhaust bends, and the full configuration of cooling holes, two cases—with and without the TBCs—were analyzed. The results reveal that the application of TBCs markedly modifies the near-wall flow structures and heat transfer characteristics. The cooling air mass flow rate decreases from 0.1211 kg/s to 0.1023 kg/s, corresponding to a 15.5% reduction in cooling load. The main recirculation zone becomes more compact, with enhanced vortex intensity, smoother velocity distribution, and improved flame stability. The high-temperature core region extends further downstream, and the peak temperature increases by approximately 80–100 K, indicating more complete combustion and greater heat retention. The outlet temperature distribution factor (OTDF) decreases from 57.34% to 44.48%, leading to a 22.4% improvement in temperature uniformity. The average wall temperatures of the inner liner, outer liner, and exhaust bend decrease by 3.7%, 8.8%, and 7.5%, respectively, with local peak reductions exceeding 250 K. The study demonstrates that the YSZ TBCs enhances the combustor’s thermal protection capability, flow stability, and temperature uniformity through a coupled mechanism of “thermal insulation–flow reconstruction–energy redistribution.” It should be noted that this study considers only the effect of the ceramic top coat of the TBCs, excluding the metallic bond coat and the thermally grown oxide (TGO) layer. Full article

Layered double hydroxides (LDHs) have gained increasing attention as versatile materials in environmental remediation, particularly for wastewater treatment. Their unique structural properties, such as tunable metal cation composition, interlayer anion exchange, and structural memory effects, make them suitable materials for a broad range of applications. In addition to these intrinsic properties, thermally treated LDH-derived mixed metal oxides have emerged as a key focus, exhibiting enhanced activity through tailored structural, electronic, and textural properties. This review presents an up-to-date and systematic overview of recent advancements in the design and application of LDH-based materials, with a focus on photocatalytic degradation of organic dyes, adsorption of contaminants, and light-activated antimicrobial activity. The review also explores emerging photocatalytic applications in correlation with surface engineering, heterojunction formation, and thermal activation to enhance the overall efficiency. In addition, the synergy between antimicrobial activity and photocatalysis is discussed in the context of achieving multifunctional microbial control in water treatment. Finally, current challenges and future perspectives are addressed, including recyclability, scale-up potential, and the development of LDH composites as sustainable alternatives to conventional photocatalysts. This review aims to support researchers in advancing LDH-based technologies toward more efficient and versatile environmental remediation solutions. Full article

This work presents the design, fabrication and characterisation of an improved textile energy storage device implemented in a single layer of polyester cotton and silk fabric. To achieve this, the energy storage device has evolved from an electrical double-layer (EDL) supercapacitor to a zinc-ion supercapacitor (ZHSC) with an optimised co-polymer membrane containing a polyethene oxide (PEO) additive and a polyvinylidene (PVDF)-based organic electrolyte. The flexible textile ZHSC achieved an areal capacitance of 159.5 mF cm⁻² and an energy density of 52.3 µWh cm⁻² (increasing by a factor of 4 and 1.8, respectively, on the previous work) with a power density of 0.27 mW cm⁻² and good bending stability. Full article

2,5-diformylfuran (DFF) is a significant biomass derivative that is employed in a variety of industries. One approach to synthesizing it is through the oxidation of 5-hydroxymethylfurfural (HMF). The challenges in DFF production arise from the need for extreme conditions, issues with overoxidation, and the limitations of noble materials used in neutral or acidic environments. By using a mildly alkaline electrolyte, DFF can be produced electrochemically alongside hydrogen gas generation, eliminating extreme conditions and allowing for the study of a wide range of transition metals. Moreover, the performance of bimetallic electrocatalysts has been studied, and it has been found to be more active in many kinds of processes, particularly Layered Double Hydroxides (LDH). Electrodeposition, once widely chosen among various LDH production methods, is preferred for producing controlled and uniform thin layers. This work examines the electrocatalytic properties of NiCo-LDH and NiFe-LDH in the production of DFF. Cobalt, which exhibits strong adsorption, will be compared to iron, which has a weak adsorption characteristic toward HMF. This study demonstrates that NiCo-LDH gives 1.49 V vs. RHE onset potential, 600 mV lower compared to NiFe-LDH (1.55 V vs. RHE) for HMF oxidation reaction. NiCo-LDH also converts twice the amount of HMF compared to NiFe-LDH for the same amount of charge passed at 0.25 mA/cm⁻² in 0.1 M Na₂B₄O₇. However, strong adsorption promotes reactant activation and reduces the energy barrier while reducing DFF selectivity in NiCo-LDH (23.4%) due to overoxidation, compared to NiFe-LDH (31.6%). In order to achieve optimal electrocatalyst performance, a careful balance of adsorption strength and reaction pathway management is required. Proper optimization of these parameters is essential to improve efficiency and selectivity in the electrocatalytic process. Full article

CO₂ mixing is one of the implementation techniques of carbon capture utilization and storage (CCUS) in concrete to tailor the performance of cementitious materials and reduce the carbon footprint. Therefore, increasing the total amount of carbon capture capacity of cement-based materials has become the key point of recent research. This study investigates the influence of Cal-Al layered double oxide (LDO) and mixing parameters on key properties of cement pastes under CO₂ mixing, including mechanical performance, microstructure, phase assemblages, and carbon capture capacity. A particular emphasis was placed on evaluating a novel bubble mixing technique, which was developed to enhance the conventional atmospheric mixing process. The results indicate that, compared to the traditional method, bubble mixing reduced the mixing intensity by 10% but increased the effective carbon sequestration capacity by 0.68%. The observed strength reduction after bubble mixing was consistent with higher water adsorption, indicating the formation of a more porous structure. A higher carbon capture efficiency was achieved with bubble mixing compared to atmospheric mixing, as revealed by further investigation. Crucially, the introduction of LDO significantly enhanced the carbon capture capacity, with improvements of up to 34% compared to the groups without LDO. This highlights the substantial potential of LDO in reducing the carbon footprint of cementitious materials and offers a novel insight for enhancing CO₂ mixing in cement. Full article

Chloride-ion (Cl⁻)-induced corrosion of steel bars is a major threat to the durability of marine concrete structures. To address this, a type of calcined CaFeAl-layered double oxide (LDO-CFA) with different calcination temperatures was used to enhanced the Cl⁻ adsorption, compressive strength, and corrosion resistance of sulphate-resistant Portland cement (SRPC)-based materials. Experimental results demonstrated that LDO-CFA exhibited high Cl⁻ adsorption capacity in both CPSs and cement-based materials. Specifically, LDO-750-CFA reached 1.98 mmol/g in CPSs—60.1% higher than LDHs-CFA—and followed the Langmuir model, indicating monolayer adsorption. It also reduced the free Cl⁻ content of SRPC paste to 0.255–0.293% after 28 days, confirming its sustained adsorption over extended curing. Furthermore, LDO-CFA positively influenced the compressive strength at all curing ages. At an optimal dosage of 0.8 wt.%, LDO-750-CFA paste significantly improved the compressive strength, increasing it by 22.1% at 7 days and 15.6% at 28 days compared to the control. Electrochemical analysis confirmed the superior corrosion resistance of the LDO-750-CFA system. The property enhancement originated from LDO-750-CFA’s synergistic effects, which included pore refinement, increased tortuosity, Cl⁻ adsorption by structural memory, a PVP-induced passive film, and PVP-improved dispersion. Overall, this work provides a framework for developing LDO-750-CFA-based composites, paving the way for more durable marine concrete. Full article

The mixed metal oxides (MMOs) derived from layered double hydroxides (LDHs) are a typical class of porous materials and have attracted significant attention across various fields due to their high surface area, rich porous structures and various compositions. Regulating the pore structure of MMOs remains an urgent need because of the growing demand for numerous applications including adsorption, catalysis, and energy conversion. Controlling the lateral size of the lamellar crystals in the Co–Al LDH precursor allowed us to engineer the pore structure of Co–Al MMO, an architecture formed by the stacking of these lamellar flakes. The pore size distribution of the Co–Al MMO has been adjusted in the range from several nanometer to hundreds of nanometers. The sample with the optimized pore sizes exhibited a much higher catalytic reaction rate in the aerobic oxidation reaction of benzyl alcohol, about 4.2 times that of the control sample. Further research demonstrated that the high activity was favored by the improved mass transfer rate in the optimized pore architecture. Moreover, sodium silicate was employed as a cross-linking agent to enhance the cohesion within the secondary particles, which consist of stacked lamellar flakes. The resulting silicate-modified Co–Al MMO demonstrated significantly improved catalytic durability, maintaining stable performance over five consecutive reuse cycles—the performance that substantially exceeded that of its un-modified counterpart. Full article

The widespread presence of bisphenol A (BPA), a persistent endocrine-disrupting pollutant, in aquatic environments poses significant ecological and health risks, necessitating its effective removal. However, conventional remediation technologies are often hampered by catalysts with narrow pH adaptability and poor stability. In this study, a novel catalyst, Zeolite-supported Cu₃Mn-layered double hydroxide (LDH), was fabricated using the co-precipitation method. The synthesized catalyst was applied to activate peroxymonosulfate (PMS), effectively enabling decomposition of BPA by advanced oxidation processes. The composite material was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM), which confirmed the successful synthesis of the zeolite-supported Cu₃Mn-LDH. The catalyst exhibited high activity in both neutral and strongly alkaline environments, achieving complete degradation of 10 mg⋅L⁻¹ bisphenol A (BPA) within 40 min and a 98% total organic carbon (TOC) removal rate when both the PMS and catalyst were dosed at 0.15 g⋅L⁻¹. Singlet oxygen was detected as the primary reactive species responsible for BPA degradation, as verified by quenching experiments and EPR analysis, which also identified the presence of sulfate (SO₄^•−), hydroxyl (•OH), and superoxide (•O₂⁻) radicals. The catalyst exhibited excellent reusability, maintaining high catalytic efficiency over two consecutive cycles with minimal performance loss. Gas chromatography-mass spectrometry (GC-MS) analysis revealed five intermediate products, enabling the proposal of potential BPA degradation pathways. This work not only presents a novel synthetic approach for zeolite-supported LDH composites, but also offers a promising strategy for the efficient removal of BPA from aqueous systems through AOPs. Full article

Rubber material with high elasticity and viscoelasticity has become the most widely used universal material, and the study of the aging failure mechanism of rubber has been meaningful research in the polymer materials field. Cis-polyisoprene was employed to analyze the mechanism of oxidative degradation under artificial UV irradiation, and the GQDs/g-C₃N₄ photocatalysis with a 2D layered structure prepared by the method of microwave-assisted polymerization enabled to accelerate the degradation procedure. The results showed that the oxidation of cis-polyisoprene occurred during the irradiation for 3 days and the structure of cis-polyisoprene changed. The α-H of the double bond was attacked by oxygen to form hydroperoxide. Then, aldehydes and ketones generated as the addition reaction of double bonds occurred. The content of the hydrogen of C=C reduced, and the oxidative degradation was dominant at the initial aging stage. The crosslinking reaction was dominant at the final aging stage and the average molecular weight decreased from 15.49 × 10⁴ to 8.78 × 10⁴. The GQDs could promote the charge transfer and the photodegradation efficiency and inhibit the electron–hole recombination. The light capture ability of GQDs was improved after compositing with g-C₃N₄. The free radicals ·O₂²⁻ generated after adding GQDs/g-C₃N₄ nanoparticles, and the molecular weight of cis-polyisoprene decreased to 5.79 × 10⁴, with the photocatalytic efficiency increasing by 20%. This work provided academic bases and reference values for the application of photocatalysts in the field of natural rubber degradation and rubber wastewater treatment. Full article