High-entropy alloys (HEAs) have attracted growing attention owing to their exceptional combination of strength, ductility, corrosion resistance, and thermal stability, which originate from their unique multi-principal-element characteristics and high mixing entropy. However, in the pursuit of extreme mechanical properties, traditional HEAs still face challenges such as room-temperature brittleness, limited work-hardening capacity, and the inherent trade-off between strength and ductility. Recent advances in nanostructure engineering have opened new pathways to push the performance limits of HEAs by controlling precipitation behavior, interface coherency, and hierarchical structural organization. This review provides a comprehensive synthesis of recent progress in nanostructure-strengthened HEAs, with emphasis on nanoprecipitation strengthening, nanocrystalline strengthening, and composite nanostructure strengthening. It analyzes their mechanisms of action and synergistic effects, summarizes the main fabrication routes and performance characteristics of nanostructure-strengthened HEAs, and discusses their potential applications under extreme environments. Finally, emerging trends are outlined toward cost-effective alloy design, predictive microstructure control, and scalable manufacturing, which are essential for translating laboratory achievements into practical implementation. Nanostructure strengthening strategies provide an effective pathway to enhance the overall performance of HEAs and establish a robust foundation for their engineering applications in aerospace, energy, tooling, and protective coatings.

Owing to their high energy and power densities, lithium-ion batteries are widely recognized as fundamental components of modern electrochemical energy storage systems for electric vehicles and grid-scale energy storage. However, long-term stability and intrinsic safety remain critical challenges that limit commercial deployment. Increasing evidence indicates that battery degradation and severe failure events are closely associated with the evolution of internal dynamic interfaces. This review establishes a full lifecycle, multiscale framework for dynamic interface evolution in lithium-ion batteries, explicitly linking nanoscale interfacial chemistry, mesoscale structural and transport heterogeneity, macroscale performance degradation, and safety failures. By correlating cross-scale interface dynamics with battery aging and thermal runaway behavior, this study provides an integrated mechanistic foundation for advanced diagnostics, modeling, and early warning strategies.

With the increasing global demand for critical minerals and low-impact subsurface energy systems, efficient and sustainable rock preconditioning methods are urgently needed. Slow-release energy material agents (SREMAs) are promising next-generation materials for enhancing rock permeability, with potential applications in mineral recovery, geothermal stimulation, and underground hydrogen storage. However, their broader adoption has been limited by suboptimal expansive pressure and a lack of mechanistic understanding. This study addresses both challenges by incorporating sodium hydroxide (NaOH) as an inorganic accelerator to enhance the performance and reveal the underlying expansion mechanism. Seven SREMAs formulations with varying NaOH contents were evaluated using the outer pipe method, and three representative samples were characterized using inductively coupled plasma mass spectrometry, scanning electron microscopy, and X-ray diffraction. The results show that NaOH accelerates hydration reactions and increases 24-h expansive pressure by 15.03% to 52.62%, with a peak performance at 0.15wt% NaOH. NaOH addition promoted the formation of calcium hydroxide and ettringite and optimized the microporous structure of calcium silicate hydrate, the latter playing a critical role in transforming internal expansion into effective outward pressure. A novel mechanistic framework linking mineralogical transformations to enhanced macroscopic performance is proposed. This study provides new insights into sustainable rock preconditioning and offers a foundation for optimizing SREMAs for applications in which low-carbon, high-efficiency subsurface engineering is essential.

Malachite, a typical copper oxide ore, exhibits strong hydrophilicity; therefore, it also exhibits poor flotation recovery. In this study, sulfidation roasting was applied as a pretreatment strategy to improve the flotation efficiency of malachite. Pyrite was used as the sulfidation agent during roasting, the feasibility of which was verified using thermodynamic calculations. Microflotation experiments demonstrate that the flotation recovery of malachite increased by nearly 70% compared with that of the untreated sample. X-ray diffraction analysis indicates that the malachite decomposed into CuO during roasting and mainly formed CuS and Cu₂S after sulfidation. This result was further supported by X-ray photoelectron spectroscopic analysis, which revealed the presence of S (S²⁻, S₂²⁻, and S_n²⁻) and Cu (Cu⁺ and Cu²⁺) species in different oxidation states on the surfaces of the roasted sample, as well as a notable decrease in oxygen content. In addition, the formation of copper sulfides disrupted the original porous structure, which led to a decrease in internal pore size. The contact angle increased from 43.71° to 89.29° after sulfidation roasting, indicating that the hydrophobicity of malachite improved markedly. Zeta potential results further indicate that the surface electronegativity increased owing to the adsorption of S species. Overall, sulfidation roasting using pyrite improved the floatability of malachite by generating hydrophobic copper sulfides on the mineral surfaces, thereby demonstrating its potential as an effective pretreatment for copper oxide ores.

Current research predominantly focuses on high-phosphorus iron ore (HPIO), where phosphorus mainly exists in the form of apatite. The reaction pathways of apatite during direct reduction have been elucidated. However, studies on phosphorus-bearing minerals within iron oxides themselves remain limited, and the transformation behavior of phosphorus associated with these iron minerals during reduction is not well understood. This study investigated the removal behavior of phosphorus within iron minerals during a direct reduction followed by magnetic separation process (DRMSP). FactSage software, X-ray diffraction (XRD), X-ray photoelectron spectrometer (XPS), and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM–EDS) were employed to elucidate the reaction mechanisms of phosphorus within iron minerals and the intrinsic relationship between iron reduction and phosphorus transformation. The results demonstrated that under the condition of 10wt% straw-derived biochar usage and reduction at 1200°C for 70 min, direct reduced iron (DRI) was obtained with an iron grade of 94.79wt%, iron recovery of 75.07%, phosphorus content of 0.09wt%, and phosphorus removal rate of 90.56%. Mechanism analysis confirmed that phosphorus within the iron minerals reacted with calcite to form apatite during the reduction of magnetite and hematite to wustite. The reduction of apatite was governed by the availability of free silica. The formation of fayalite consumed free silica, inhibiting the reduction of apatite. Conversely, the reduction of fayalite released free silica, which promoted the reduction of apatite. The elemental phosphorus generated then reacted with metallic iron to form an iron–phosphorus alloy.

The melting point of slag plays a pivotal role in determining the process stability and product quality during electroslag remelting (ESR). However, accurate prediction remains challenging due to the scarcity of experimental data, the compositional complexity of slag systems, and the limited accuracy of conventional empirical models. In this study, a robust multi-task neural network framework based on experimental-and-auxiliary data fusion is developed to predict the melting points of ESR slags. The framework combines one experimental melting-point source dataset with two auxiliary augmented datasets: (i) experimentally measured melting points, (ii) melting-point estimates derived from viscosity inflection points using the viscosity prediction model, and (iii) melting-point values generated from empirical correlations. A multi-task learning architecture is constructed, comprising one primary task (experimental data) and two auxiliary tasks (augmented datasets), enabling effective knowledge transfer and joint optimization through a custom-designed loss function and adaptive task-weighting scheme. Error analysis results demonstrate that the proposed method consistently outperforms traditional machine learning models and single-task neural networks across multiple evaluation metrics, including mean squared error (MSE), mean absolute error (MAE), and mean absolute percentage error (MAPE). In addition, the model exhibits excellent robustness and physical consistency, providing a promising solution for intelligent slag system design and process optimization in ESR operations.

The content of Si₈Al₆Fe₄Ca in metallurgical-grade silicon (MG-Si) influences the yield of (CH₃)₂SiCl₂. However, due to the limitations of the refining and solidification processes of MG-Si, enhancing the endogenous Si₈Al₆Fe₄Ca content is challenging. In this study, a method for synthesizing Si₈Al₆Fe₄Ca was developed by designing FeSi₂–Al–Si₂Al₂Ca multiphase reaction diffusion couple experiments. Additionally, the mechanism underlying the formation of Si₈Al₆Fe₄Ca: 4FeSi₂ + Si₂Al₂Ca + 4A1 = Si₈Al₆Fe₄Ca + 2Si (1173 K) was elucidated. The results showed that the addition of an appropriate amount of Al to the FeSi₂–Si₂Al₂Ca reaction system with a mass ratio of 1:1 increased the yield of Si₈Al₆Fe₄Ca to 44.9wt%. However, the Si₂Al₃Fe generated from the direct reaction of FeSi₂ and Al contaminated the synthetic product. Incorporating Al in the form of Si(Al) solid solution within the Si₂Al₂Ca phase reduced the excessive generation of Si₂Al₃Fe from FeSi₂ and Al. The optimal component ratio of Si₂Al₂Ca was Si: Al: Ca = 27.45wt%:52.95wt%:19.60wt%, which reduced the conversion rate of FeSi₂ to Si₂Al₃Fe from 55.06% to 43.8%. Furthermore, the optimal mass ratio of FeSi₂ to Si₂Al₂Ca was 1:0.45, which increased the content of Si₈Al₆Fe₄Ca in the synthetic product to 65.74wt%. This study presents an economical and convenient method to increase the content of Si₈Al₆Fe₄Ca in MG-Si, laying a theoretical foundation for improving the efficiency of synthesizing (CH₃)₂SiCl₂ from MG-Si.

A low-melting-point molten salt composed of NaCl, CaCl₂, and MgCl₂ was developed via thermodynamic calculations and experimental validation. A set of thermodynamic database for the NaCl–CaCl₂–MgCl₂ molten salt was built. The molten salt composition was optimised based on the phase diagram calculations, and the melting point measured in the experiment was 418.5°C. The molten salt was purified by adding excess Mg, resulting in a final Mg content of 738.0 µg/g. Compared with the NaCl–CaCl₂–MgCl₂ salt, the Mg-containing salt exhibited enhanced thermal stability, with a reduced weight loss of only 5.0wt% at 728.0°C. The average specific heat capacities of the solid and liquid phases were measured at 0.89 and 1.44 J/(g °C), respectively, indicating improved heat retention. Notably, the differences in the melting temperature and fusion enthalpy remained negligible. For the first time, the ultrafast dynamics of this ternary molten salt were characterized using polarization-selective mid-infrared pump-probe spectroscopy. The Mg²⁺ vibrational dynamics (4.5 ps) were slower than those of the water peak (2.3 ps), whereas the behavior of the water peak closely resembled that in pure water. Collectively, this study enriches the physicochemical database of molten salt and offers theoretical and technical guidance for salt purification, with significant implications for the comprehensive utilization of salt-lake resources with abundant reserves in China.

This study investigates the effects of prior austenite grain size (PAGS) ranging from 22 to 62 µm on the crystallographic characteristics and hierarchical structures of bainite and martensite in a high-strength low-alloy steel. Bainite dominates when the PAGS ≤ 52 µm, whereas martensite prevails at a PAGS of 62 µm owing to elevated martensite start temperature. Using electron backscatter diffraction analysis and prior austenite orientation reconstruction, the crystallographic characteristics (variant selection and variant pairing) were analyzed, and more than 100 prior austenite grains (PAGs) were examined per specimen. As the PAGS increased, the total average number of variant types per PAG in the bainite specimens was 14.6, 14.1, and 18.3, thus indicating weakened variant selection at larger PAGSs. Smaller PAGs tend to form fewer variant types owing to insufficient autocatalytic nucleation. Variant pairing in the bainite specimens shows a decrease in the fractions of variant 1 (V1)/V2 and V1/V4 pairs and an increase in the fraction of V1/V8 pairs as the PAGS increases. By contrast, the martensitic specimen favors the formation of variants within the same close-packed plane (CP) group, particularly the self-accommodating V1/V2 pair. This is attributed to the enhanced austenite matrix strength and the reduction in transformation temperatures at finer PAGSs, which promotes the self-accommodation of transformation strain. Regarding hierarchical structures, for PAGS measuring ≤ 52 µm, the number of packets, Bain grains, blocks, and sub-blocks per PAG decrease and their mean area decreases with their size primarily due to spatial constraints. A PAGS of 62 µm results in packet coarsening, whereas other hierarchical structures undergo refinement. This study provides a statistical framework for analyzing the crystallographic characteristics and hierarchical structure of steels, thus offering insights into the optimization of bainitic and martensitic transformations through PAGS regulation.

Hydrogen embrittlement poses a critical challenge limiting the widespread application of high-strength steels. Although introducing nanoscale precipitates and elemental segregation at grain boundaries (GBs) has emerged as a promising strategy to enhance material performance, the atomic-scale mechanisms by which alloying elements influence hydrogen behavior through GB segregation and precipitate interactions remain insufficiently understood. To address this gap, this study integrates a custom-developed deep potential (DP) with Monte Carlo (MC) and molecular dynamics (MD) simulations to systematically investigate the synergistic effects of elemental segregation and hydrogen diffusion in Fe–Mn–V–C–B–H multi-component alloys. The developed DP model exhibits exceptional consistency with density functional theory (DFT) in predicting GB energies, GB segregation energies, and elastic constants, significantly surpassing conventional empirical potentials. MD simulations reveal that manganese (Mn) segregation at GBs substantially suppresses hydrogen diffusion, with the inhibitory effect intensifying as Mn concentration increases. Simultaneously, the vanadium carbide/alpha-iron (VC/α-Fe) interface, characterized by periodic lattice matching, functions as an efficient hydrogen trap, effectively localizing hydrogen atoms and reducing their diffusion within the matrix. This work elucidates atomic-scale mechanisms of hydrogen embrittlement in multi-component alloys, highlighting the efficacy of machine-learning potentials (MLPs) for guiding targeted elemental segregation and precipitate engineering to develop hydrogen-resistant structural materials.

This study investigates the influence of composite shear flow casting (CSFC) in enhancing the microstructural homogeneity and tensile properties of Cr–Ni–Mo–V steel compared to conventional solidification (CS). In the as-cast state, CSFC significantly increased the equiaxed grain fraction from 9.7% to 56.3%, decreased the texture index from 12.81 to 4.68, and reduced the segregation of Nb, C, Mo, Cr, and V. Following post-forging annealing, CSFC samples exhibited a refined, equiaxed microstructure with grain sizes ranging from 3.78 to 5.72 µm, in contrast to the distinct banded structure observed in CS samples. Furthermore, CSFC enhanced yield strength through pronounced grain boundary strengthening (contributing 259 to 319 MPa) and promoted tensile isotropy by impeding crack propagation along columnar grain boundaries and banded interfaces, which were prevalent in CS samples and led to inconsistent ductility (9.3% to 14.5%). Consequently, CSFC samples achieved uniform elongation (11.4%–12.4%) across all directions, attributed to a homogeneous microstructure that effectively dispersed stress and suppressed localized crack growth, thereby simultaneously enhancing both strength and ductility.

The mechanism of intermetallic compounds (IMCs) along the thickness direction on crack formation in thick plate Al/Mg friction stir welded (FSW) joints remains unresolved. This study investigates the effects of strain gradient, mismatch, and fracture toughness on crack formation. The results indicate that the cracks are exclusively formed in the upper of the stir zone and at the Al/Al₃Mg₂ interface. Crack formation in the upper of the stir zone is associated with the eutectic reaction (Al + Al₃Mg₂ ↔ Liquid). The Al/Al₃Mg₂ interface exhibits the highest lattice mismatch (δ = 2.27%) and misorientation gradient (0.7°), which corresponds to the preferential crack initiation site. In addition, nanoindentation tests confirm that the Al₁₂Mg₁₇ phase (0.41 MPa·m^1/2) possesses higher fracture toughness than the Al₃Mg₂ phase (0.28 MPa·m^1/2). Therefore, controlling the thickness of the Al₃Mg₂ phase is essential for suppressing crack formation. These findings provide a theoretical basis for crack suppression in thick Al/Mg FSW joints and are valuable for further improving joint quality.

This study investigates the microstructural evolution and mechanical behavior of Ti–4Al–0.005B alloy T-joints subjected to friction stir welding (FSW) and annealing at 600 and 700°C. Multi-scale characterization is used to reveal relationships between the annealing temperature, microstructure, and properties. The results show that annealing at 600°C significantly promotes dynamic recrystallization (DRX) within the stir zone (SZ), resulting in a fine equiaxed α-phase microstructure, with a recrystallization fraction of 69.27% and high-angle grain boundaries (HAGBs) content of 74.48% in the bottom regions of the SZ. In contrast, the thermo-mechanically affected zone (TMAZ) and heat-affected zone (HAZ) exhibit incomplete recrystallization, retaining a substantial fraction of low-angle grain boundaries (LAGBs). Annealing at 700°C enhances the DRX driving force but also causes abnormal grain growth, reducing the SZ recrystallization fraction to 52.25% and HAGBs content to 51.90%. Kernel average misorientation (KAM) analysis reveals a decrease in the residual dislocation density after annealing at 700°C, indicating enhanced recovery and corresponding grain coarsening, which contribute to a decrease in peak hardness (from HV 340.7 to HV 332.1). Texture analysis shows a pronounced weakening of the basal texture in the SZ at higher temperature (intensity drop from 30 to 15 mud), corroborating the increased DRX activity. Mechanical testing demonstrates that while annealing at 700°C slightly reduces strength, it significantly enhances ductility (elongation from (6.18 ± 0.35)% to (7.25 ± 0.83)% and impact toughness (from (28.13 ± 2.13) to (47.81 ± 4.77) J/cm²). An annealing temperature of approximately 650°C is thus recommended to balance strength and toughness in FSW-treated Ti–4Al–0.005B alloy T-joints.

High-entropy Ti₄₀Zr₂₀Nb₂₀Hf₅Ta₁₅ (at%) alloy was melted under a high nitrogen pressure (40 bar) using an inductive cold crucible, yielding a nitrogen-saturated alloy. The as-cast microstructure is complex, comprising nitride dendrites enriched in Ti, Zr, and Hf that occupy approximately 48% of the volume. These dendrites are surrounded by an interdendritic body-centered cubic solid solution matrix enriched in Nb and Ta. Additionally, two distinct nitride phases, such as (ZrHf)N and (TiZrHf)N, form needle-like precipitates within the interdendritic regions. The nitrogen-saturated alloy exhibits a compressive strength of 2159 MPa with negligible plastic deformation, and a hardness of HV (684 ± 6). This strength is significantly higher than that of the precursor alloy, primarily due to the reinforcing effect of the dendritic nitrides and the fine precipitates in the interdendritic matrix. Ab initio density functional theory calculations confirm the stability or metastability of the experimentally identified nitride phases. The overall phase constitution and segregation are governed primarily by strong metal–nitrogen chemical interactions (enthalpy), while configurational entropy mainly contributes to chemical disorder within the individual phases.

In this study, an optimal combination of mechanical strength, stress relaxation resistance, and conductivity was achieved in a Cu–Be alloy by controlling the precipitate distribution. The precipitation behaviors of the Cu–Be alloy aged at 360°C revealed that the size, morphology, and distribution of precipitated phases can be effectively controlled, enabling the alloy to attain a tensile strength exceeding 1043 MPa. With a reasonable proportion of precipitates, the corresponding electrical conductivity and stress relaxation resistance can reach more than 30.8% IACS and 96.7%, respectively. By correlating the morphology, size, and distribution of precipitated phases with the stress relaxation resistance of the Cu–Be alloy, kinetic equations for the stress relaxation behaviors of the alloy were established in this study. Correspondingly, the stress relaxation rates (SRR) of the alloy were predicted after different stress relaxation times.

This study addresses the corrosion and scaling issues of metallic materials in high-salinity environments. Three commonly used scale inhibitors and corrosion inhibitors—polyaspartic acid (PASP), polyepoxysuccinic acid (PESA), and hydroxyethylidene diphosphonic acid (HEDP)—were selected for multi-component formulations. High-throughput screening methods were employed to efficiently identify the optimal component ratios with the best synergistic effects for both scale and corrosion inhibition. The optimal ratios of ternary components of PASP: PESA: HEDP were found to be 1:1:2 and 2:1:1. The corrosion inhibition performance of the selected multi-component inhibitors was then systematically assessed using electrochemical impedance spectroscopy (EIS), and the results showed that the inhibition efficiency at the optimal concentration reached 89.1%. Additionally, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) were used to characterize the corrosion and scaling surfaces of the treated Q235 steel, as well as the crystal structure of the generated CaCO₃ precipitates. Further investigation of the mechanisms underlying both scale and corrosion inhibition enabled the development of a rapid and precise approach for assessing the performance of formulated inhibitor systems.

Laser-directed energy deposition (L-DED) has attracted significant attention for its potential to rapidly produce advanced ceramics, which could benefit various industries. Nevertheless, the quality and properties of ceramics manufactured through L-DED still require enhancement to ensure their sustainable application in industry. Here, high-performance Al₂O₃ ceramics were produced using L-DED by adding small amounts of SiO₂. The effects of this doping on the surface bonding quality, microstructure, and mechanical properties of the obtained ceramic materials were thoroughly investigated. The results indicate that SiO₂ doping significantly enhances the surface bonding quality of the deposited cylindrical samples. The complete elimination of intergranular voids between adjacent interlayers, a denser microstructure, and the emergence of small bulges on the sample surfaces evidence this improvement. Additionally, the elliptical pores previously present at the edges of the samples have vanished, resulting in tighter intergranular bonding between the grains and a noteworthy increase in relative density. Remarkably, doping with α-cristobalite produced the highest recorded average flexural strength and fracture toughness of the deposited ceramics, achieving values of (483.47 ± 38.84) MPa and (4.87 ± 0.80) MPa·m^1/2, respectively. These findings establish SiO₂ doping as an effective method for successfully fabricating high-performance Al₂O₃ ceramics through L-DED.

Significant progress has been observed in steel slag recycling. However, advanced approaches for minimizing metal-element-abundant residues have rarely been adopted. In this work, we present a facile strategy to tailor steel slag surface and use various metal components of steel slag to construct MgAl-carbonate layered double hydroxide (LDH)-supported iron sulfide nanocomposites (FeS-LDH-CO₃) using a filtrate rich in Fe³⁺, Mg²⁺, and Al³⁺ ions after steel slag dissolution. Two-dimensional intercalated FeS-LDH-RCOO nanosheets were then obtained by exchanging carboxylate anions derived from acetic, chloroacetic, dichloroacetic, n-propionic, or acrylic acids with carbonate anions within the FeS-LDH-CO₃ structure. The FeS-LDH-RCOO nanocomposites were characterized via X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, thermogravimetry–derivative thermogravimetry, the Brunauer–Emmett–Teller method, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results revealed that poorly crystalline FeS was uniformly dispersed on LDH nanosheets, leading to FeS-LDH-RCOO nanocomposites with a high specific surface area and special composite structure. In addition, FeS-LDH-RCOO exhibited outstanding Cr(VI) detoxification performance in designed case studies. Acetate-intercalated FeS-LDH (FeS-LDH-CH₃COO) exhibited a Cr(VI) adsorption capacity of 36.1 mg/g resulting from the synergy of the simultaneous immobilization of Cr(VI) on LDH nanosheets and reduction of Cr(VI) to Cr(III) on FeS. The fabricated FeS-LDH-RCOO composite not only utilizes various components of steel slag while minimizing metal element-abundant residues but also possesses good Cr(VI) cleaning ability because of the integration of FeS and MgAl-carboxylate LDH. Thus, this study provides a new method for the reasonable and extensive utilization of steel slag in environmental cleaning applications, transforming a waste material into a valuable resource.

Spent automotive three-way catalysts (TWCs) are important secondary resources with high recycling value owing to their high concentrations of precious metals, including Pd, Pt, and Rh. Recently, photocatalytic technologies have been explored for the recovery of platinum group metals (PGMs). However, existing studies have predominantly focused on new TWCs or metallic elements as model materials. The composition of new TWCs differs significantly from that of spent TWCs, which contain complex mixtures of carrier materials, oil and carbon deposits, and oxidized precious metals. In this study, TiO₂ was loaded onto the surface of diatomite using typical sol–gel method, followed by a solvothermal process to integrate BiOCl with TiO₂/diatomite, thereby successfully preparing a ternary BiOCl–TiO₂/diatomite composite photocatalyst. Under ultraviolet irradiation, the prepared material exhibited superior PGM leaching efficiency compared with the commercial P25 catalyst. The leaching efficiencies reached 98.58% for Pd, 97.30% for Pt, and 65.37% for Rh. The results demonstrated that the incorporation of diatomite preferentially exposed the BiOCl (001) facets, thereby enhancing photocatalytic activity. Furthermore, a systematic analysis of changes in liquid-phase composition and reactive radical species elucidated the key mechanism responsible for PGM leaching from spent TWCs.

Molten salt electrolytic graphitization is an efficient and green pathway for the electrochemical conversion of biomass resources into high-value-added graphitized carbon. However, this process exhibits poor reaction kinetics and difficult structural modulation. In this paper, we report the process and mechanism of graphitization and tubulation of Fe-assisted molten salt CaCl₂ at low temperatures. Experimental results showed that Fe assistance significantly enhanced the graphitization rate, shortened the reaction time, and reduced the energy consumption. Fe also induced the evolution of the product morphology from a sheet structure to a tube–sheet hybrid structure. Experimental and simulated multiscale analyses revealed the kinetics of the Fe-promoted deoxygenation reaction and its pathway, as well as the mechanism of Fe-regulated directed growth of carbon rings to construct tube–sheet composite structures. The resulting graphitized carbon exhibited a specific capacity of 336.37 mAh·g⁻¹ at 1 C (1 C = 372 mA·g⁻¹)) when used as a negative electrode for lithium-ion batteries. This electrochemically coupled Fe-catalyzed synergistic strategy provides a rational pathway for the high-value utilization of low-quality carbon-containing solid waste (e.g., woody biochar).

The high-entropy strategy has recently gained significant attention as an effective approach for enhancing microwave absorption performance. In this paper, a simple hydrothermal method followed by calcination was used to synthesize Fe_0.2Co_0.2Ni_0.2Cu_0.2Zn_0.2Fe₂O₄ high-entropy spinel ferrite for microwave absorption. The effects of calcination temperature on the microstructure and microwave absorption performance of the material were systematically investigated. Phase analysis reveals that a pure spinel ferrite phase with microwave absorption capability forms at 400°C, while minor maghemite impurities emerge at 800°C. As temperature rises, the effective absorption bandwidth first increases and then decreases, with its frequency range shifting toward higher frequencies. The sample calcined at 400°C achieves an excellent reflection loss of −77.48 dB with an effective absorption bandwidth of 3.74 GHz. The sample optimized at 800°C exhibits an excellent absorption bandwidth of 6.71 GHz (10.61–17.32 GHz), along with a minimum reflection loss of −31.17 dB at a thickness of only 2.19 mm. It also demonstrates a significant radar cross-section reduction of 26.04 dB·m². The excellent microwave absorption performance is primarily attributed to enhanced dipole polarization induced by the high-entropy effect, favorable electrical conductivity, effective magnetic loss, and adequate impedance matching. This work provides a good example for constructing high-performance spinel oxides through high-entropy strategies, demonstrating significant potential in the development of advanced microwave absorption materials.

Perovskite memristors are usually fabricated by the traditional spin-coating method in a glove box, restricting them to small-area films. Herein, we blade-coated large-area three dimensional (3D) Cs_0.09FA_0.91PbI₃ and one dimensional (1D) (CH₃)₃SPbI₃ surface under air condition to create a heterojunction synaptic memristor with enhanced stability and functionality. The 3D/1D heterojunction memristor exhibits excellent resistive switching properties, with on/off ratio increasing from 10 to over 70, remaining stable after 300 cycles at 0.5 V, and retaining resistance states for over 10³ s. Blade coating, a solution-based technique compatible with roll-to-roll processing, enables large-area fabrication (10 cm ×10 cm substrates) with cost-effectiveness, supporting scalability for mass production. The device successfully emulated synaptic plasticity, including long-term potentiation, long-term depression, paired-pulse facilitation, and spike frequency/voltage-dependent plasticity.

Metal–halide perovskites have been successfully utilized in high-sensitivity direct X-ray detection, and the further integration of perovskites with pixel chips is crucial for X-ray imaging. In this study, an ingenious interface-bonding strategy is applied to integrate a polycrystalline CsPbBr₃ wafer with a thin-film transistor (TFT) array. A polyimide–CsPbBr₃ composite binder with satisfactory mechanical adhesion and optoelectronic properties is synthesized and used to integrate a freestanding CsPbBr₃ wafer with a TFT array. Under low-temperature annealing, interface reconstruction occurs with the in-situ formation of a homogeneous bridging structure between the CsPbBr₃ wafer and TFT array, achieving a multichannel X-ray imaging detector. The X-ray detector exhibits a high sensitivity of 4310 µC·Gy⁻¹·cm⁻² and low detection limit of 442 nGy·s⁻¹. The resulting imaging panel with pixels offers a satisfactory spatial resolution (2.2 LP·mm⁻¹) X-ray imaging.