Ultra-high temperature ceramic (UHTC) structural materials have emerged as critical candidates in the fields of aerospace, defense equipment, energy and power sectors due to their outstanding oxidation/ablation resistance, high-temperature strength retention, and thermal shock resistance in oxidative environments exceeding 1600 ℃. In recent years, extensive research has been achieved in both fundamental research and technological applications focusing on compositional control, structural design, fabrication techniques, and performance optimization of these materials. UHTC systems, characterized by carbides, borides and nitrides, are currently facing increasingly stringent demands for enhanced thermal performance in more complex environments. To further advance development of UHTC structural materials for such conditions, this paper systematically reviews the latest research progress in this field. Firstly, synthesis techniques of UHTC powders are elaborated. Subsequently, systems, densification methods and structural regulation strategies of UHTCs are presented. Furthermore, fabrication techniques and performance enhancement strategies of UHTC matrix composites (UHTCMCs), UHTCs modified carbon/carbon composites (UHTCs-C/C), and UHTC coatings are examined, with particular emphasis on the latest breakthroughs in oxidation/ablation resistance. Additionally, primary technical challenges related to the long-term stability and reliability of UHTC structural materials under extreme conditions are identified, and a forward-looking perspective on future development trends is provided.

In regard to the crucial role of nerves in tissue regeneration, developing tissue engineering scaffolds with neural-activities has attracted more attention. Recently, inorganic biomaterials have been extensively used in regulating neural cell functions and innervated tissue regeneration due to their advantages of highly controllable chemical compositions, micro/nano topographical structures, and excellent physicochemical properties. This review firstly introduces the typical used inorganic biomaterials for neural regulation, including bioceramics and electroactive materials, and then elaborates on their biological effects of enhancing neural cell viabilities and functions through modulating cell behaviors, regulating immune microenvironment, and constructing electroactive microenvironment. Subsequently, recent progress of inorganic biomaterials on various innervated tissue regeneration, such as spinal cord, peripheral nerves, skin, skeletal muscles, and cavernous tissues, is summarized. Finally, the current challenges and future perspectives of inorganic biomaterials in innervated tissue regeneration are discussed.

Cardiovascular disease is the leading cause of death worldwide, with myocardial infarction (MI) being a serious threat to human health and life. Current pharmacological and surgical interventions primarily serve as palliative measures, failing to address the root cause of cardiomyocyte death post-MI. Recent advances in regenerative biomedical materials, however, offer promising solutions. Inorganic bioactive materials, capable of interacting with cells and tissues to activate cellular responses and modulate tissue regeneration, have garnered significant attention in regenerative medicine and tissue engineering. Silicate-based biomaterials (e.g., bioceramics, bioactive glasses), carbon-based nanomaterials, and metal oxides exhibit remarkable potential in promoting myocardial repair and regeneration. This review highlights the latest progress in inorganic bioactive materials for myocardial regeneration and repair, elucidates their material categories and mechanisms of action, and discusses current challenges in clinical translation, while providing insights into future research directions.

Extensive skin trauma represents one of the most challenging issues in global public health, and its repair and treatment impose a huge economic burden on healthcare systems. Therefore, there is an urgent need to develop an efficient wound dressing that can promote skin regeneration at the wound site. In recent years, silicate bioceramics/bioglasses have received widespread attention and application in the field of wound healing due to their multiple advantages, including promoting angiogenesis, stimulating collagen deposition, and anti-infection properties. This paper provides a concise overview of the mechanisms through which silicate-based bioceramics/ bioglasses contribute to skin regeneration, analyzes their integration with emerging technologies and their applications in wound healing, and summarizes the advantages and limitations of these materials. This review aims to inform and guide the future clinical application of silicate-based bioceramics/bioglasses in wound healing.

Bioactive glass (BG) is an important class of amorphous inorganic biomaterials, which has been clinically used in hard tissue repair for many years, exhibiting unique tissue repair activity. Recent studies have found that BG also shows effective repair activity in soft tissue, demonstrating significant application potential. Compared with traditional BG, micro-nanoscale bioactive glass (MNBG) has a unique micro-nano structure, which not only retains its excellent chemical composition but also has a larger specific surface area and higher reactivity. These special structures and properties enable MNBG to exhibit significant application potential in promoting vascularization and skin repair/regeneration. This work focuses on the research progress of MNBG in regulating vascularization and skin regeneration, including the abilities of MNBG to promote vascularization and regulate immune cell function, as well as its antioxidant, anti-inflammatory, and antibacterial properties. These characteristics enable MNBG to effectively stimulate blood vessel formation, reduce inflammation, and inhibit bacterial infection, thus promoting wound healing and tissue repair. This paper summarizes the key research on the role of MNBG in vascularization and skin wound repair and offers recommendations on the existing issues and future research directions in the application of MNBG in skin wound repair, aiming to promote the application transformation of MNBG in the field of skin repair.

Hair loss caused by hair follicle degeneration can seriously affect individuals' quality of life and mental health. However, the clinical treatment methods for hair loss have several limitations. Hair follicle regeneration has emerged as a significant challenge in the field of skin tissue engineering. In recent years, various inorganic materials, particularly bioceramics, have been identified as capable of regulating cell activities by releasing bioactive ions, which positively influences skin tissue repair and hair follicle reconstruction. Herein, the structures of skin tissue and hair follicle are introduced firstly, then the main types of bioceramics that can promote hair follicle regeneration are listed, followed by the related representative studies. Subsequently, the different application forms of inorganic materials in hair follicle regeneration are discussed. Finally, the development direction of bioceramics for hair regeneration is summarized and prospected. This review highlights the potential of bioceramics in promoting hair regrowth, offering new strategies for treating hair follicle damage and hair loss disorders.

As an effective in vitro three-dimensional (3D) model, organoids can simulate the structure and function of corresponding tissues/organs, demonstrating broad application prospects in the biomedical field. The construction of organoids relies on the regulation of stem cell behaviors and multicellular interactions. Inorganic bioactive materials possess excellent biocompatibility and bioactivity, showing wide application in the field of biomedical research. Therefore, they can potentially regulate cell behaviors and cell-cell/cell-matrix interactions in the construction of organoids. In this review, the role of inorganic bioactive materials in organoid research was explored, emphasizing their contribution to organoid development and application, and summarizing the critical steps in organoid construction strategies. Subsequently, the biological functions of inorganic bioactive materials, particularly those compatible with key steps in organoid construction, were systematically elucidated, and the key mechanisms by which inorganic bioactive materials promote organoid development and application were emphasized, including their effects on key signaling pathways, regulations of matrix material properties and cellular energy metabolism. In addition, the application of organoids as auxiliary tools to promote the use of inorganic bioactive materials was reviewed. Finally, the strategies for further advancing organoid research by regulating various physical and biochemical clues provided by inorganic bioactive materials were prospected.

Two-dimensional (2D) inorganic materials, as a class of inorganic ultrathin nanosheets with single or several atomic layers, exhibit high specific surface area, high electrical conductivity and/or photothermal conversion efficiency. These unique physicochemical properties confer procoagulant, antibacterial, anti-inflammatory, and antioxidant biological effects. In recent years, in view of degradation and metabolism issues, these materials have been explored for modulation of diseased skin tissues, such as full-thickness wounds, burns and diabetic wounds, demonstrating remarkable effects in accelerating wound healing, alleviating infections and improving the inflammatory microenvironment. This review focuses on the unique structure and biological effects of 2D inorganic materials, systematically describes their applications in wound healing and related mechanisms, and looks forward to current challenges and prospects of 2D inorganic materials in the field of skin repair.

Piezoelectric materials, which serve as converters between mechanical energy and electric energy, are important functional materials. Recently, the technology for textured piezoelectric ceramics has become an important technical approach for developing the next generation of high-performance piezoelectric materials. By tailoring grain orientation, textured piezoelectric ceramics exhibit properties akin to single crystals, exhibiting enhanced piezoelectric and electromechanical properties, as well as improved thermal stability. Furthermore, as polycrystalline ceramics, textured ceramics inherit the advantages of traditional ceramic materials, including ease of fabrication, favorable mechanical properties, and suitability of special-shape and syntype. This paper provides a brief introduction to texturing technique, development of perovskite templates for textured ceramics, and research results related to lead titanate (PbTiO₃, PT) based textured piezoelectric ceramics. It systemizes the development and status of the piezoelectric textured ceramics while summarizing their technical advantages. Additionally, the existing scientific problems and future challenges of PT-based textured piezoelectric ceramics are analyzed, focusing on the suitability of templates and matrix via theoretical prediction, the relationship between microstructure and macroscopic properties of textured ceramics, and piezoelectric devices based on textured piezoelectric ceramics. By reviewing the PT-based textured piezoelectric ceramics, this paper aims to provide an in-depth introduction to texturing techniques and theories, seeks to enhance understanding of textured piezoelectric ceramics, and promotes the development of high- performance piezoelectric materials. This work is expected to benefit the breakthrough innovation and leap forward development of next generation high-end piezoelectric devices.

Alkaline water electrolysis (AWE) faces challenges of low efficiency and high costs due to its relatively low current density. It is necessary to develop efficient and stable non-precious metal electrocatalysts under high current densities. In this study, an amorphous NiMoOP/NF electrocatalyst was fabricated by the hydrothermal method combined with phosphorization on a nickel foam (NF) substrate. The amorphous needle-like morphology effectively increases active sites and enhances the stability of hydrogen production through water electrolysis. At current densities of 10 and 1000 mA·cm^-2, the hydrogen evolution overpotentials are 31 and 370 mV, respectively, and the catalyst stably runs for 1100 h at a high current density of 1 A·cm^-2. The NiMoOP/NF material, when integrated with crystalline silicon heterojunction solar cells for overall water splitting, achieves a theoretical solar-to-hydrogen conversion efficiency of up to 18.60%. Under industrially relevant conditions (60 ℃, 30% (in mass) KOH electrolyte), the electrolysis voltage is 1.77 V, enabling a current density of 400 mA·cm^-2, with a hydrogen production energy consumption of 4.19 kWh·Nm^-3 (Nm³: Normal cubic meter). Economic analysis of photovoltaic-powered hydrogen production via electrolysis indicates that the minimum hydrogen production cost for an off-grid and non-storage photovoltaic hydrogen production system is ¥28.52 kg^-1. The amorphous nanoneedle-like materials developed in this study significantly enhanced both hydrogen evolution activity and stability during water electrolysis, providing valuable insights for design of high-current-density hydrogen evolution catalysts. Furthermore, the combined economic analysis of photovoltaic electrolysis for green hydrogen production supports advancement of green hydrogen industry.

Control and removal of volatile organic compounds (VOCs) have always been critical issues in the environmental field. Catalytic oxidation has emerged as one of the most promising technologies for VOCs removal due to its low operational temperature, high efficiency, and non-toxic by-products. Perovskite oxides (ABO₃) are recognized as efficient and stable catalysts for the catalytic oxidation of VOCs. To enhance the catalytic efficiency of perovskite-based catalysts, it is necessary to systematically analyze and optimize the design of perovskite oxides to meet the specific requirements for the removal of different VOCs. This paper comprehensively reviews recent advances in the catalytic oxidation of VOCs using perovskite oxides. Firstly, various design strategies for perovskite oxides in the catalytic oxidation of VOCs, including morphology control, A-site and B-site substitution, defect engineering, and supported perovskite catalysts, are introduced, giving a close link between the catalytic performance of perovskite oxides and their material composition, morphology, surface properties (oxygen species, defects), and intrinsic properties (oxygen vacancy concentration, lattice structure). The reaction mechanisms and degradation pathways involved in the catalytic oxidation of VOCs are analyzed, and the prospects and challenges in the rational design of perovskite oxide catalysts and the exploration of reaction mechanisms are outlined.

Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP), one of the NASICON-type solid-state electrolytes, possesses a high ionic conductivity, excellent chemical stability, and high shear modulus (40-60 GPa). However, the tetravalent titanium ion in LATP is particularly prone to undergo reduction reaction with lithium metal during cycling, leading to the structure degradation and electron introduction in LATP electrolyte. In order to maintain the chemical and electrochemical stability of LATP, this work modified the surface of LATP solid electrolyte with a Prussian blue (PB) interfacial layer to optimize the contact between electrolyte and anode. Using PB with abundant open-frame lithium ion diffusion channels as the mixed conductive modification layer has several advantages. (1) Intrinsic conductivity of PB layer is enhanced after lithiation, accelerating homogenized transmission of electrons from the interfacial layer to the negative electrode. (2) Lithiation process is accompanied by enhancing lithium affinity of PB intermediate layer, which enables the interface contact between LATP and lithium metal to be closer during the electrochemical process. (3) Lithiated PB still maintains a three-dimensional skeleton structure, which is conducive to the homogenization effect of lithium ion flux at interface, thereby promoting stabilization of lithium deposition/stripping process. (4) The PB with metal-organic framework (MOF) structure is conducive to ensuring the mechanical stability of interface during cycling and reducing volume change of lithium negative electrode. (5) The PB structure does not collapse after lithiation, not easy to cause phase separation and additional phase boundaries or phase gaps, which is conducive to the integration of lithium ion flow and electron flow. (6) More uniquely, redox potential of PB is higher than those of lithium metal and LATP on both sides of the PB interface, conducive to the formation of an electron transport barrier between Li and LATP, and prevents the reduction and degradation of LATP. The improved solid-state battery has good cycling stability and kinetic performance. At a current density of 0.025 mA·cm^-2, the PB-modified Li/Li symmetric solid-state cell can achieve a stable cycle of 800 h. After 160 cycles at a current density of 0.025 mA·cm^-2, the capacity of PB-modified Li/LiFePO₄ solid-state battery is still close to 200 mAh·g^-1. The modified Li/FeF₃ solid-state battery can be operated at 0.025 mA·cm^-2 with the preservation of a high Coulombic efficiency, indicating that the PB modification has good tolerance to the volume change generated during electrochemical cycling.

In the post-Moore era, temporary bonding and ultra-thin wafer thinning of large-size functional wafers have emerged as essential technologies underpinning innovation within the semiconductor industry. However, challenges such as wafer warpage and breakage commonly encountered during wafer thinning severely limit device performance and yield. To address these issues, WAN’s group at Yongjiang Laboratory developed a cost-effective, room-temperature ultra-flat temporary bonding technique. This innovative process has significantly reduced the risk of wafer warpage while achieving high flatness and stability in wafer bonding. By integrating this process with domestically developed thinning equipment, the group successfully thinned 8-inch silicon wafers down to 8 µm, 12-inch silicon power chips to 15 µm with a total thickness variation (TTV) ≤2 µm, and 8-inch lithium niobate wafers to 8-10 µm, thereby satisfying diverse piezoelectric micro-electro-mechanical system (MEMS) application demands. Currently, this technology is widely applied in heterogeneous integration of various wafer materials, including silicon, lithium niobate/lithium tantalate, gallium oxide, and indium phosphide, providing crucial support for the localization and development of power chips and high-performance MEMS devices.

Pb(Zr,Ti)O₃ (PZT) ceramics play a crucial role in fields such as national defense, healthcare, communication, and energy conversion due to their excellent piezoelectric, ferroelectric, and pyroelectric properties. However, the sintering temperature of PZT ceramics usually exceeds 1200 ℃, resulting in high energy consumption and a large amount of PbO volatilization. This volatilization disrupts the stoichiometric balance of PZT ceramics, thereby adversely affecting their electrical properties. Moreover, the rapid development of piezoelectric multilayer devices further requires PZT ceramics to be co-sintered with low-cost metal electrodes at low temperatures. To address these challenges, researchers have extensively investigated the low-temperature sintering of PZT piezoelectric ceramics, successfully reducing the sintering temperature of PZT ceramics to below 1000 ℃, which has attracted widespread attention. Starting from the structural characteristics and physical properties of PZT ceramics, this article reviews the current research status of low-temperature sintering technology in the field of PZT ceramics. It mainly introduces the current status of low-temperature sintering techniques, including spark plasma sintering, hot-pressing sintering, cold sintering, as well as the use of sintering aids such as forming solid solutions, liquid-phase sintering, and transient liquid-phase sintering. The influence of these sintering techniques on the microstructure and electrical properties of PZT piezoelectric ceramics is systematically summarized. The issue of electrical performance degradation caused by sintering aids and possible solutions are analyzed. At last, future development trends of low-temperature sintering technologies for PZT ceramic are explored.

Volatile organic compounds (VOCs) pose significant risks to environmental quality and human health. To enhance adsorption performance of adsorbents for VOCs, further improvement of the unsaturated metal centers becomes a key factor based on the principle that metal ions can be replaced in metal organic frameworks (MOFs). Here, a one-step solvothermal synthesis system was utilized to dope abundant, cost-effective, and environment friendly Al³⁺ ions into MIL-101(Cr) for preparing Al-MIL-101(Cr). Morphologies and structures of MIL-101(Cr) and Al-MIL-101(Cr) samples, alongside the static adsorption performance for toluene, n-hexane, oil and p-xylene, were analyzed. Static adsorption capacities of toluene, n-hexane, oil, and p-xylene of MIL-101(Cr) were 0.676, 0.621, 0.451 and 0.812 g·g^-1, respectively. When Al³⁺ doping amount reached 0.75 mmol, Al-0.75-MIL-101(Cr) displayed maximum VOCs adsorption capacities (0.911 g·g^-1 for toluene, 0.755 g·g^-1 for n-hexane, 0.713 g·g^-1 for oil, and 0.875 g·g^-1 for p-xylene). The dynamic toluene adsorption behavior was assessed through single-component breakthrough curves. Both dynamic and static adsorption results demonstrate that Al-MIL-101(Cr) possesses excellent VOCs removal capabilities, which are attributed to the extensive specific surface area and augmented unsaturated metal sites.

Microwave dielectric ceramics are the key basic materials of 5G/6G communication technology, with particular emphasis on the materials that exhibit a high quality factor (Q×f), low dielectric constant (ε_r) and near-zero temperature coefficient of resonant frequency (τ_f). However, most low-ε_r materials tend to have a significantly negative τ_f value. This study provides a systematic overview of the classical ionic polarizability dilution mechanism and phase transition mechanism, along with the structural factors affecting τ_f, such as unit cell volume mechanism, oxygen polyhedron distortion, bond energy, bond ionicity, and bond valence. Subsequently, the anomalous changes in τ_f in the cubic normal and inverse garnet systems without phase transition are described in detail. The “Rattling” effect is introduced as a novel mechanism affecting the τ_f of microwave dielectric ceramics. Cations involved in “Rattling”, characterized by high coordination and weak chemical bonds, are the primary factors affecting the overall microwave dielectric polarization and loss of the material. This phenomenon results in an increase in ionic polarizability and ε_r, a forward shift in τ_f and a reduction in Q×f value, which has been verified and applied in many different material systems. Furthermore, the introduction of a weighted function for total ion polarization deviation serves to evaluate the impact of the entire molecule's “Rattling” and “Compressed” effects on ε_r. A novel concept of temperature coefficient of ionic polarizability (τ_αm) is also proposed, allowing for quantitative calculation. This simplifies the factors that affect the positive and negative of dielectric constant temperature coefficient (τ_ε), by relating it to ε_r, τ_αm and linear expansion coefficient α_L.

As classical cathode materials of solid oxide fuel cell (SOFC), Fe-based perovskite materials are favored for their affordable price, low thermal expansion coefficient and high stability. In this study, B-site high-entropy perovskite oxide La_0.7Sr_0.3(FeNiCo)_0.8Mo_0.1Ti_0.1O_3-δ (LSFNCMT) was prepared by the citric acid-nitrate combustion method. Due to the faster oxygen surface exchange rate of the high-entropy material, the LSFNCMT cathode shows excellent oxygen reduction reaction (ORR) activity with a polarization impedance (R_p) of 0.11 Ω·cm² at 800 ℃, which is much lower than that of the La_0.7Sr_0.3FeO_3-δ (LSF) cathode (0.31 Ω·cm²). Furthermore, the high-entropy material exhibits superior stability due to incorporation of highly acidic Ni, Co, and Mo cations as well as Ti cation with more negative average bonding energy (ABE) of metal-oxygen. In the 22 h-stability test of the symmetric cell with LSFNCMT cathode in the Cr-containing atmosphere, R_p only increases from 1.07 Ω·cm² to 2.98 Ω·cm², while R_p of the LSF cathode increases from 2.62 Ω·cm² to 7.90 Ω·cm² under the same conditions, indicating better Cr-resistance of LSFNCMT due to the high-entropy strategy. The fact that the maximum power density (MPD) of the single cell with LSFNCMT cathode at 800 ℃ is 1105.26 mW·cm^-2, significantly higher than that of LSF cathode (830.74 mW·cm^-2), and R_p at 800 ℃ is 0.24 Ω·cm², lower than that of LSF cathode (0.36 Ω·cm²), confirming excellent toxicity resistance of the high-entropy cathode. This study shows that B-position high entropy is an effective way to improve the catalytic activity and chromium resistance of cathode materials.

Human soft tissue generally refers to the sum of all connective tissues in the body excluding bones and joints, including skin, muscles, blood vessels, nerves, etc., and is the most widely distributed and largest proportion of tissues in the human body. Soft tissues are soft and elastic, which closely connect various tissues and organs, and play a crucial role in supporting, protecting, and maintaining the normal physiological functions of human body. However, large-area and large-volume soft tissue injuries caused by accidents, diseases, and surgery significantly affect health and quality of life of patients, and remain one of the significant challenges in clinical medicine. Due to its effective performance of repairing damaged tissues, autologous transplantation has been regarded as the gold standard in clinical applications for many years, while it faces the disadvantages of limited donor sources and secondary trauma. Therefore, it is urgent to develop novel bioactive materials with suitable compositions/structures and excellent performance to promote soft tissue regeneration.

Since the bioactive glass, the first-generation inorganic biomaterials, with excellent biocompatibility and tissue integration functions invented by Prof. Larry Hench from the United States in 1969, the research curtain of bioactive inorganic materials has been opened, receiving widespread attention from material scientists and medical doctors, and entering a fast track of rapid development. Inorganic biomaterials possess highly controllable chemical compositions and macro/nano topographical structures, offering unique advantages in regulating cell differentiation and inducing tissue regeneration. Over the past decades, researches have mainly focused on the effects of inorganic biomaterials on regulating the differentiation behaviors of bone-related cells and hard tissue regeneration including bone and teeth, effectively addressing several clinical problems. Interestingly, recent studies demonstrate that inorganic biomaterials also have the capacity to regulate the bioactivity and specific differentiation of various soft tissue-related cells, including vascular endothelial cells, nerve cells, hair follicle stem cells, etc. These studies preliminarily confirm the potential application of inorganic biomaterials in repairing soft tissue injuries, greatly expanding the application scope of inorganic biomaterials.

In recent years, our group has performed numerous studies on the application of bioactive inorganic materials for soft tissue regeneration, and achieved some representative results. To showcase the latest research progress of Chinese research teams in the application of inorganic biomaterials to soft tissues regeneration including skin, nerves, myocardium, etc., and attract more researchers to participate in the basic research and clinical translation of inorganic biomaterials, Prof. Chang Jiang and I are invited by the editorial office of Journal of Inorganic Materials to serve as guest editors for a special issue on the theme of "Inorganic Biomaterials for Soft Tissue Regeneration". This special issue includes review articles on the latest researches from well-known teams, including Shanghai Institute of Ceramics, Chinese Academy of Sciences, Xi'an Jiaotong University, Sichuan University, Shanghai Normal University, etc., covering many interesting aspects such as vascularized skin regeneration, hair follicle regeneration, innervated tissue regeneration, myocardial regeneration, and organoid development.

We hope that this special issue can help researchers gain a deeper understanding of the latest developments and broad application prospects of inorganic biomaterials in the field of soft tissue regeneration, and promote close collaboration among researchers from various fields and disciplines to jointly advance the development of inorganic biomaterial science. We expect that more innovative inorganic bioactive materials will emerge to solve numerous clinical problems related to soft tissue regeneration in the future, ensuring human life safety and health.

Volatile organic compounds (VOCs) and NO_x are important precursors of PM_2.5 and O₃, and their excessive emissions have significant negative impacts on environmental quality and human health. Compared with ordinary VOCs, nitrogen-containing volatile organic compounds (N-VOCs) need more complex environmental control strategies due to their nitrogen heteroatoms. Therefore, development and application of control technologies for N-VOCs have become a current research hotspot. In order to achieve the two key objectives of low-temperature high catalytic activity and high N₂ selectivity in catalytic oxidation system of N-VOCs, there is an urgent need to design efficient and low-cost catalysts. This paper systematically summarizes the research progress of mineral materials, metal materials, single atom catalysts (SACs) and molecular sieves in catalytic oxidation of common N-VOCs (N,N-dimethylformamide, acrylonitrile, acetonitrile, n-butylamine, triethylamine, etc.), and describes the sources and hazards of N-VOCs. The key factors affecting catalytic oxidation of amines, nitriles and other typical N-VOCs are summarized, including catalytic activity, catalyst physicochemical properties, catalytic constitutive relationship and reaction mechanism. It is proposed that secondary pollutants should be avoided from deep oxidation of intermediate products in catalytic oxidation of N-VOCs. Finally, the prospects and challenges on catalytic oxidation of N-VOCs are discussed, aiming to provide theoretical guidance and practical cases for clearing N-VOCs in the future.

The rapid development of communication technology has put forward increasingly stringent requirements on dielectric ceramic filters. Efficient design of novel dielectric materials to facilitate their progression is of great significance. The relationship between structure and performance of materials is crucial for the synthesis and design of microwave dielectric ceramics. The P-V-L bond theory aims to provide crystal structure parameters and basic chemical bond characteristics through calculations, such as the bond ionicity, bond covalency, bond sensitivity, lattice energy, and bond energy. These parameters provide a theoretical basis and guidance for modification design of microwave dielectric ceramics. In recent years, researchers have been committed to applying the P-V-L bond theory to a large number of ceramic systems to explain the relationship between structure and performance of microwave dielectric ceramics. Based on this theory, new modification strategies have been proposed to obtain excellent microwave dielectric properties. This review provides a comprehensive overview of the fundamental concepts of the P-V-L bond theory and the binary bonding formula of complex polycrystals, and outlines the methods of calculating chemical bond parameters and chemical bond characteristics in the field of microwave dielectric ceramics. Meanwhile, the application of the P-V-L bond theory in several common microwave dielectric ceramic systems in recent years is analyzed. Data from literatures show that the P-V-L bond theory analysis can provide the bond characteristics in ion-doped modified systems, as well as the structural evolution and dielectric properties. This understanding is highly significant for guiding development and application direction of microwave dielectric ceramics.

Lithium niobate (LiNbO₃, LN) is an artificial crystal with excellent physical properties, such as acousto-optic, electro-optic, piezoelectric, and photorefractive performance. It is not only seen as "optical silicon", but also suggests that humans are entering the era of "Lithium Niobate Valley". Its excellent optoelectronic properties have a wide potential application in emerging fields, such as artificial intelligence and photoelectric hybrid module. Photorefraction was found and proved to be an important property of LN crystal. With development of optoelectronic devices based on LN to micro- and nano-scale, photorefractive effect has gradually appeared. Single crystal LN is the basic material for preparing various devices taking advantage of lithium niobate on insulator (LNOI). The photorefractive properties can be adjusted by doping appropriate impurity ions. Compared with normal ions (valence < +5 (valence of niobium ions)), incorporation of high-valence ions (valence ≥ +5) can be more beneficial to improve photorefractive performances of LN crystals in recent years. This paper summarizes research progress of high-valence ion-doped LN crystals of which doping with V, Mo, U, and Bi ions can effectively adjust their photorefractive properties, suitable for designing micro-ring resonators, optically programmable photonic components, nonlinear photonic devices, and other micro- and nano-scale devices. Finally, based on above advances in high-valence ion doped LN, further research may achieve unprecedented improvements in four aspects: high-quality and big-size crystal growth, photorefractive mechanism, ion doping with lone-pair electrons, and novel optoelectronic devices.

Lead-based textured piezoelectric ceramics have significantly lower production costs compared to single crystals with performance that notably exceeds that of non-textured ones. They are regarded as the most promising alternative to lead zirconate titanate polycrystalline ceramics and have emerged as a key research topic in the materials science field in recent years. This paper provides a comprehensive overview of the growth principles and characterization methods for lead-based textured piezoelectric ceramics, including the preparation processes for templates, and the essential steps involved in production of these ceramics. Then, it summarizes representative research findings on lead-based textured piezoelectric ceramics and systemizes various improvement strategies. From the perspective of material formulation, the component ratios of ternary and binary system textured piezoelectric ceramics are typically chosen at the phase boundary to ease flipping of polar states under an external electric field, thereby achieving a high piezoelectric coefficient (d₃₃). Both systems exhibit similar d₃₃, but Curie temperature of the ternary system is generally higher than that of the binary system, indicating greater application potential. From the perspective of preparation processes, the addition of sintering aids can significantly promote oriented growth of grains and post-annealing can eliminate impurities at grain boundaries and void defects. Moreover, quenching can freeze the electric dipoles from a disordered state. These improvements in processing have significantly enhanced the performance of lead-based textured piezoelectric ceramics. Finally, this paper analyzes the current issues and developmental challenges, concluding that differences in lattice parameters and valence states of B-site ions between the template and the matrix material are the primary factors limiting the performance of lead-based textured piezoelectric ceramics. Customizing templates that match well with different matrix materials will further improve their performance.

Garnet-type solid electrolytes (LLZTO) have attracted tremendous attention in the past few years, owing to their high ionic conductivity and wide electrochemical stability window. However, the poor wettability with lithium metal and severe lithium dendrite formation during cycling greatly hindered their application in large-scale devices. In this study, a composite anode (LAF) was prepared by melting Li metal and AlF₃, which eventually formed fluorides (LiF, AlF₃) and Li-Al alloys. Elemental distribution analysis revealed that a fluoride layer was formed at LLZTO|LAF interface upon contact with LLZTO. Compared to metallic lithium, the composite anode formed a significantly smaller interface contact angle with LLZTO, notably improving the interfacial wettability. As a result, the modified LAF3|LLZTO interface (a mass ratio of Li to AlF3 is 3 : 1) exhibits an ultralow interfacial resistance of 3.9 Ω/cm², which is much lower than that of the lithium anode with LLZTO (138.6 Ω/cm²). Meanwhile, the critical current density of the composite anode with LLZTO increases from 0.2 mA/cm² to 0.8 mA/cm². LAF|LLZTO|LAF symmetric cells demonstrate stable plating/stripping for 3500 h under a current density of 0.2 mA/cm², illustrating the good stability of lithium-ion plating/stripping process. LiFePO₄|LLZTO|LAF quasi-solid-state battery delivers a high discharge capacity of 151.1 mAh/g at 0.1C rate (1C=170 mA/g) and retains 96.5% of its initial capacity after 240 cycles at 1C rate. The LAF composite anode demonstrated in this study effectively decreases the interfacial resistance between LLZTO and anode, and stabilizes lithium-ion plating/stripping process, offering a promising approach for designing high-performance LLZTO-based lithium metal batteries.

Diamond with excellent properties and broad application prospects in the fields of thermal management of optics and electronic devices, and wide bandgap semiconductors, is known as the ultimate semiconductor. As an optical window, a large-sized CVD (chemical vapor deposition) diamond free-standing thick film with a thickness of ≥2 mm is required. In semiconductor heat dissipation, a diamond free-standing film with a diameter over 4 inches (1 inch=2.54 cm) and a thickness of 100 μm is required to bond with semiconductor materials such as gallium nitride (GaN). However, there still exist significant difficulties in synthesis and application of large-area CVD diamond films. On the one hand, stress during the deposition process can cause the diamond film to rupture. On the other hand, residual stress can cause the diamond film to warp, resulting in poor bonding quality. Therefore, controlling the stress of diamond films has become a key issue for the large-scale and widespread application of diamond films. This article summarizes the classification, sources, and influencing factors of CVD diamond stress, and provides a detailed introduction to measures for suppressing stress in diamond films. Furthermore, researches on improving diamond properties by artificially applying stress are summarized, including changing diamond bandgap and increasing diamond thermal conductivity under stress. Finally, a method and theoretical calculation formula for evaluating the stress magnitude of diamond are provided, and the future trend of stress research on diamond films is analyzed.

Pb(Zr,Ti)O₃-Pb(Zn_1/3Nb_2/3)O₃ (PZT-PZN) based ceramics, as important piezoelectric materials, have a wide range of applications in fields such as sensors and actuators, thus the optimization of their piezoelectric properties has been a hot research topic. This study investigated the effects of phase boundary engineering and domain engineering on (1-x)[0.8Pb(Zr_0.5Ti_0.5)O₃-0.2Pb(Zn_1/3Nb_2/3)O₃]-xBi(Zn_0.5Ti_0.5)O₃ ((1-x)(0.8PZT-0.2PZN)- xBZT) ceramic to obtain excellent piezoelectric properties. The crystal phase structure and microstructure of ceramic samples were characterized. The results showed that all samples had a pure perovskite structure, and the addition of BZT gradually increased the grain size. The addition of BZT caused a phase transition in ceramic samples from the morphotropic phase boundary (MPB) towards the tetragonal phase region, which is crucial for optimizing piezoelectric properties. By adjusting content of BZT and precisely controlling position of the phase boundary, the piezoelectric performance can be optimized. Domain structure is one of the key factors affecting piezoelectric performance. By using domain engineering techniques to optimize grain size and domain size, piezoelectric properties of ceramic samples have been significantly improved. Specifically, excellent piezoelectric properties (piezoelectric constant d₃₃=320 pC/N, electromechanical coupling factor k_p=0.44) were obtained simultaneously for x=0.08. Based on experimental results and theoretical analysis, influence mechanisms of phase boundary engineering and domain engineering on piezoelectric properties were explored. The study shows that addition of BZT not only promotes grain growth, but also optimizes the domain structure, enabling the polarization reversal process easier, thereby improving piezoelectric properties. These research results not only provide new ideas for the design of high-performance piezoelectric ceramics, but also lay a theoretical foundation for development of related electronic devices.

Sodium-ion batteries (SIBs) have emerged as a significant alternative to lithium-ion batteries, offering a cost-effective and safe solution with promising potential in energy storage. Among these, P2-type Ni/Mn based oxides possess the advantages of high theoretical capacity and wide operating voltage. However, the P2-O2 phase transition under high voltage and Jahn-Teller aberration significantly impact the cycling reversibility and structural stability. To address the above issues, here, P2-type Na_0.8Ni_0.33Mn_0.67-xAl_xO₂ materials with different doping contents of Al using a high-temperature solid-phase method were prepared, and employed as cathodes for sodium-ion batteries. It was observed that Al doping resulted in strengthening of their metal-oxygen bonds (M-O bonds) and expansion of the distance of Na layer, thereby facilitating Na⁺ diffusion and enhancing structural stability. The electrochemical properties demonstrated that Al doping could impede the high-voltage phase transition, stimulate the electrochemical activity of Mn, and diminish the charge transfer resistance, leading to enhanced electrochemical properties of the materials. Among these P2-type Na_0.8Ni_0.33Mn_0.67-xAl_xO₂ materials, Na_0.8Ni_0.33Mn_0.62Al_0.05O₂ cathode displayed the optimal cycling performance with a capacity retention of 87.3% after 200 cycles at 0.1C (1C=200 mA·g^-1) in the range of 2.0-4.2 V, and the superior rate performance with a discharge specific capacity of 100.9 mAh·g^-1 at 2C in the range of 2.0-4.2 V.

Silicon carbide (SiC), as a representative wide bandgap semiconductor material, has increasingly demonstrated its significance in high-power, high-frequency and high-temperature electronic device applications. In recent years, SiC semiconductors have become primary material for power devices in electric drive modules and charging modules of new energy vehicles. Compared to Si-based insulated gate bipolar transistors (IGBTs), a kind of minority carrier device, SiC materials enable high-voltage resistance through majority carrier devices (such as Schottky barrier diodes and metal-oxide-semiconductor field-effect transistors (MOSFETs)) with high-frequency device structures, which conversely allows SiC to simultaneously achieve key characteristics of low on-resistance and high frequency. It is easy to deduce that, SiC will also play an indispensable role in emerging fields such as electric aircrafts, electric vertical take-off and landing (eVTOL) vehicles for low-altitude transportation, augmented reality (AR), photovoltaic inverters, and rail transportation. Among various SiC polytypes, 3C-SiC stands out due to its unique cubic crystal structure, higher thermal conductivity (500 W/(m·K)) and channel mobility (approximately 300 cm²/(V·s)), showcasing significant application potential and research value. This paper provides an overview of the crystal structure, fundamental physical properties, application advantages, and major growth methods of 3C-SiC, including chemical vapor deposition (CVD), continuous-feed physical vapor transport (CF-PVT), sublimation epitaxy (SE), and top-seeded solution growth (TSSG). Research progress and the latest achievements in 3C-SiC crystal growth using above techniques are reviewed, focusing on the thermodynamic characteristics and growth mechanisms of vapor-phase and liquid-phase methods. The microscopic processes of crystal growth are analyzed and summarized, and the future development directions and application prospects for 3C-SiC crystals are discussed.

BaTiO₃ multi-layer ceramic capacitors (MLCCs) are meeting the growing performance demands in consumer electronics, aerospace and defense research. Distribution and segregation of elements during complex fabrication process of MLCCs significantly affect the phase composition, microstructures and hence the performance, which necessitates an effective analytical means capable of accurately resolving elements of MLCCs at microscopic scales. Elemental analysis techniques integrated with modern transmission electron microscope (TEM) have unique advantages due to their ultra-high spatial resolution, reaching the sub-angström scale. Among them, energy dispersive X-ray spectroscopy (EDS) provides a simple and fast way for qualitative analysis of metallic elements. However, their limitations, such as low sensitivity for detecting the light element O, and more critically, low energy resolution (~130 eV), which results in the severe overlap of spectral peaks of Ba and Ti elements, hinder accurate quantitative analysis of BaTiO₃. In contrast, electron energy-loss spectroscopy (EELS) possesses ultra-high energy resolution (<1.0 eV), and can provide additional information regarding chemical valence, thus demonstrating enhanced potentials and advantages in the micro-scale elemental analysis of MLCC. In this work, EELS is employed to address the limitation of EDS in distinguishing between Ba and Ti elements due to the overlap of spectral peaks. In addition, EELS reveals that proportion of Ti³⁺ ions is higher in smaller BaTiO₃ grains. Meanwhile, EELS line-scan analysis of individual grains indicates that Ba element diffuses more easily than Ti during sintering process of ceramics. Given its high spatial resolution, EELS offers more accurate and comprehensive information on the elements and valence states, thereby providing potential support for the process improvement and performance optimization of MLCC.

Deepwater shaft sealing materials are one of the critical core technologies limiting the advancement of deepwater equipment. Silicon carbide (SiC) ceramics, due to their outstanding high modulus, high thermal conductivity, low density, and excellent corrosion resistance, have become an ideal choice for next-generation deep-sea sealing materials. The immense seawater pressure in deep-sea environments causes significant differences in corrosion and wear processes compared to conventional atmospheric pressure conditions. However, research on the corrosion and wear behavior of SiC ceramics in deep-sea environments remains relatively insufficient. In this study, the static pressure of artificial seawater was adjusted to simulate deep-sea conditions at depths ranging from 0 to 5 km. In-situ characterization of the materials’ performance in deep-sea environments was conducted, and the influence of static pressure on their corrosion and wear properties was explored. The results indicated that SiC ceramics exhibited outstanding corrosion resistance in deep-sea environments at depths between 0 and 5 km. After immersion for 200 h, no significant corrosion, oxidation, or seawater salt-related erosion was observed on the material’s surface, and no mass loss occurred. As seawater depth increased, the chemical reaction between SiC and water gradually weakened, further enhancing the corrosion resistance of SiC ceramics. After seawater corrosion, the mechanical properties of SiC ceramics remained stable. Flexural strength of the material decreased by less than 5% after 200 h-corrosion in a 5 km deep-sea environment, and Vickers hardness or fracture toughness changed little. Under seawater lubrication conditions, SiC ceramics exhibited excellent wear resistance, with a wear rate of 2×10^-8-4×10^-8 mm³/(N·m), much lower than that of the paired silicon nitride (Si₃N₄) ceramic material (4×10^-5-1×10^-4 mm³/(N·m)). Notably, as seawater depth increased, both the material’s resistance to water corrosion and the lubricating load-bearing capacity of seawater were significantly enhanced, leading to a decrease in wear rate with increasing depth. In conclusion, SiC ceramics demonstrate significant potential for application in deep-sea sealing technologies.

Silica aerogel has broad applications in the field of high-temperature thermal insulation due to its low density, low thermal conductivity and high stability. However, its thermal insulation performance deteriorates significantly at elevated temperatures exceeding 600 ℃, primarily due to the collapse of pore structure. Meanwhile, the shielding capacity of SiO₂ aerogel to the infrared radiation at high temperature is rather low due to the intrinsic properties of SiO₂. Herein, a strategy for improving the high-temperature stability and infrared shielding properties of SiO₂ aerogel via Ca doping was explored. Calcium-doped silica aerogel (CSA) powders were prepared by Sol-Gel, hydrothermal, and ambient pressure drying (APD) techniques using water glass and anhydrous calcium chloride as precursors and trimethylchlorosilane as a hydrophobic modifier. The effects of Ca/Si molar ratio in the precursor and hydrothermal conditions (temperature and pH) on the crystalline properties, microscopic morphology and pore structure of CSAs were investigated. The results show that the Ca/Si molar ratio and hydrothermal treatment have significant effects on the microstructure and heat resistance of CSAs in the temperature range of 400-1000 ℃. The samples sintered at 1000 ℃ have a high specific surface area of 100.1 m²/g and a pore volume of 0.8705 cm³/g, indicating that the CSA has good heat resistance. One-side insulation tests at temperatures up to 600 ℃ show that the sample with a Ca/Si molar ratio of 1.0 has the best insulation performance, with a cold surface temperature of 450 ℃, which is 27 ℃ lower than that of the pure silica aerogel.

MXenes, an emerging family of two-dimensional (2D) materials with high electronic conductivity, large specific surface area, good hydrophilicity, and regulable surface functional groups, have shown broad application potential across the domains of energy, catalysis, corrosion prevention, and electromagnetic shielding. Among numerous MXenes, Mo₂CT_x MXene has attracted much attention due to its excellent electrocatalytic hydrogen evolution activity. This paper aims to systematically review its preparation and current research status in the field of electrocatalytic hydrogen evolution, providing a comprehensive and clear reference framework for further in-depth study. The synthesis methodologies and exfoliation techniques in recent years are comprehensively reviewed, the important role as an electrocatalyst for hydrogen evolution reaction (HER) is summarized, and the optimization strategies for improving catalytic performance of HER are addressed from perspectives of terminated group modification, elemental doping, and hybridization. Finally, a prospective outlook regarding Mo₂CT_x MXene-based composites in the realm of electrocatalytic hydrogen evolution is presented. Despite significant research advancements on Mo₂CT_x MXene, the absence of eco-friendly and scalable preparation methodologies remains a critical challenge, contributing to elevated production costs. Additionally, the delayed progress in catalytic mechanism investigations hinders the formulation of rational design strategies. Henceforth, efforts should focus on developing green, fluorine-free synthetic approaches to facilitate large-scale material production, concurrently enhancing catalytic activity and catalyst stability, and accelerating the exploration of catalytic mechanisms. These endeavors are critical to advancing the practical application of Mo₂CT_x and its composite materials in the field of electrocatalytic hydrogen evolution.

The efficient removal of low-concentration volatile organic compounds (VOCs) in indoor and industrial environments remains a significant challenge. Metal-organic frameworks (MOFs) are potential oxidation catalysts due to their superior adsorption enrichment capability for low-concentration VOCs. In this work, hydroxyl-containing ligands were introduced into UiO-66, and the as-synthesized UiO-66-OH catalyst exhibited exceptional photothermal catalytic performance on oxidation of flowing low-concentration VOCs (initial concentrations of 0.075 mg/L for toluene and 0.064 mg/L for benzene, a weight hourly space velocity (WHSV) of 30000 mL/(g∙h)), achieving 97% and 90% conversion of toluene and benzene, respectively, surpassing the reported photothermal catalysts such as metal oxides and noble-metal-loaded catalysts. Such impressive activity is attributed to the synergy of thermal catalysis and photocatalysis. Ligand hydroxylation optimizes the electron structure and the ligand-to-metal charge transfer (LMCT) effect, enhancing light absorption, improving electron-hole separation efficiency and photothermal properties of UiO-66. Hydroxyl introduction promotes the formation of oxygen vacancies, facilitating oxygen adsorption/activation to sustain lattice oxygen (O_latt) and generate superoxide radical (∙O₂^-), which are the dominant reactive species in VOCs oxidation. This work not only presents the potential of MOFs as efficient photothermal catalysts for the oxidation of low-concentration VOCs but also shows prospects on facile modulation of electron structure by ligand engineering to enhance the photothermal properties of MOFs.

Volatile organic compounds (VOCs), particularly aromatic hydrocarbons such as toluene, pose significant threats to the environment and human health due to their high volatility and biological toxicity. Traditional metal- organic frameworks (MOFs) are primarily microporous, and their trade-off between adsorption capacity and molecular transport efficiency has driven development of more advanced material systems. In this work, graphene oxide (GO) doped metal-organic framework gels (MOGs) based on UiO-66 were developed, leveraging the synergistic modification effect of GO. The π-conjugated structure of GO enhanced π-π interactions with toluene molecules, while its abundant oxygen-containing functional groups facilitated competitive coordination with metal nodes, leading to exposure of additional Lewis acid sites and thereby enhancing metal-π interactions. Experimental results demonstrated that UG-1 with a mass ratio of GO to ZrCl₄ at 1 : 100 exhibited a breakthrough adsorption capacity of 77.4 mg/g in dynamic adsorption experiments and a saturated capacity of up to 1245.5 mg/g in static tests, outperforming both UiO66 MOF and UiO66 MOG materials. In conclusion, this study elucidates multiple regulatory mechanisms of GO incorporation in modulating pore structure and host-guest interactions, providing a new theoretical basis and practical guidance for designing efficient and recyclable VOC adsorbents.

Periodontitis is a clinical challenge caused by bacterial overgrowth, resulting in irreversible damage to periodontal tissue. Antibacterial sonodynamic therapy (aSDT) has emerged as a promising alternative to conventional debridement due to its excellent biocompatibility and tissue penetration capability. However, this therapy cannot cure the periodontitis solely, needing more exploration to find an effectively improved treatment. Here, Fe doped Ti based metal-organic frameworks (Fe/Ti-MOFs) were prepared to explore the relationship between Fe doping and sonoresponsive efficiency. Incorporation of Fe enabled precise modulation of the band structure and crystallinity while maintaining the lattice architecture. Results showed that Fe/Ti-MOFs exhibited enhanced hydroxyl radical (•OH) generation under ultrasonic irradiation, effectively facilitating the eradication of bacterial pathogens. Notably, the sample with a Fe/Ti molar ratio of 0.025 : 1 exhibited exceptional performance. The sonocatalytic activity was collectively influenced by bandgap engineering, Fe doping concentration and crystallinity. Moreover, Fe/Ti-MOFs exhibited no cytotoxicity toward gingival fibroblasts and maintained excellent biocompatibility, without adverse effects on tissue repair. The ultrasound responsive Fe/Ti-MOFs material developed in this study offers potential for mitigating the adverse effects of antibiotics and providing novel insights and strategies for the application of aSDT in periodontitis treatment.

Hybrid improper ferroelectricity (HIF) is recognized as a secondary ferroelectric phenomenon induced by coupling of in-plane rotation and out-of-plane tilt of anion octahedra in compounds with the units of perovskite structure. HIF is expected to be applicable in the multiferroic materials with strong magnetoelectric coupling owing to its intrinsic characteristic for electric-field control of magnetism, thereby greatly extending the connotation and denotation of ferroelectric physics. This paper focuses on the experimental progress of HIF materials with Ruddlesden-Popper (R-P) structure. It also establishes the linear relationship between Curie temperature (T_C) and tolerance factor (τ) of double-layered R-P oxides, elucidating the underlying physical mechanisms of HIF. Based on intrinsic electric-field control of magnetism for HIF, the detection of coexistence of polar and weak ferromagnetic phases in ferrites with double-layered R-P structures is of great scientific significance. Additionally, the documented ferroelectricity in the A-site cation-ordered triple-layered R-P oxide has significantly expanded the fields of HIF. Although significant progress has been achieved in understanding HIF in R-P oxides, more efforts should be made to explore more new material systems and single-phase multiferroic materials.

Continuous silicon carbide fiber reinforced silicon carbide (SiC_f/SiC) composites are widely utilized in the hot-end components of aero engines due to their exceptional properties and high-temperature resistance. To ensure the safety and reliability of SiC_f/SiC composite parts during service, it is crucial to investigate the evolution of their mechanical properties under prolonged high-temperature exposure. In this study, mini-SiC_f/SiC composites with a BN interface were fabricated using Cansas-II SiC fibers. These mini-SiC_f/SiC composites underwent heat treatment at 1100, 1200, and 1350 ℃ for durations of 5, 10, 50, 100, and 200 h, respectively, to examine the effects of high-temperature and long-term heat treatment on their mechanical properties and microstructure. The results show that at 1100 ℃, heat treatment has no significant impact on the mini-SiC_f/SiC composites. The mechanical properties remain largely unchanged, and the contribution fractions of each stage to the overall mechanical performance remain consistent. At 1200 ℃, short-term heat treatment shows minimal effects on the mini-SiC_f/SiC composites without notable change in tensile strength. However, prolonged heat treatment leads to damage in the SiC fibers, thereby decreasing their tensile strength. At 1350 ℃, heat treatment significantly improves the properties of the BN interface but causes severe damage to the SiC fibers, resulting in a marked decline in the mechanical properties of the mini composites. As the heat treatment duration increases, the extent of fiber damage intensifies, leading to a continuous deterioration in the mechanical performance of the composites.

Electrochromic smart windows can regulate indoor light through modulating optical transmittance of electrochromic materials to realize energy-saving buildings. Amorphous tungsten oxide (WO₃) film fabricated by magnetron sputtering technology is the most likely to be industrialized due to its advantages of large-area and uniform deposition. However, electrochromic characteristics of the sputtered WO₃ film lag behind those of the solution-process approach due to inefficient ion transport arising from its intrinsically dense atomic structure. In this work, a strategy to develop microstructured magnetron-sputtered WO₃ films by introducing the buried porous electrodes to improve the optical modulation and response time was proposed. The results demonstrate that the porous sputtered WO₃ films prepared by this method exhibit significantly enhanced electrochromic characteristics compared with the dense WO₃ films. When thickness of the porous WO₃ increased to 300 nm, the optimized electrochromic characteristics were achieved, with a remarkable optical modulation of up to 79.08%, coloring and bleaching times of only 2.6 and 2.0 s, and a high coloring efficiency of 52.5 cm²/C. The improved performance is mainly attributed to synergistic effect of the porous indium tin oxide (ITO) electrode and the porous WO₃ film. The porous ITO electrode can increase the surface area with the increased WO₃ component and then increase electronic charges, facilitating the redox reaction process. Moreover, the porous WO₃ film offers a larger surface area for the electrolyte, increases reactive active sites and shortens ion diffusion pathway, which accelerates the ion diffusion and migration process, realizing efficient redox reactions and fast ion transport. This work provides an effective method for preparing high-performance micro- and nano-structured sputtered electrochromic films.

Traditional wave-absorbing materials often exhibit performance limitations at high temperatures, which makes it difficult to meet performance demands in extreme high-temperature environments. Fe₂AlB₂ has garnered significant attention in the field of high-temperature wave absorption due to its nano-layered structure and exceptional high-temperature stability. This study synthesized Fe₂AlB₂ powder through a wet ball milling process followed by sintering in an argon atmosphere. Investigation was conducted to elucidate the oxidation mechanisms and to assess the evolution of its wave-absorbing properties at elevated temperatures. Additionally, electromagnetic simulation software was utilized to model the radar cross-section associated with its absorption process under 7 GHz microwave irradiation. The results indicate that the onset oxidation temperature of Fe₂AlB₂ is 671 ℃. As the oxidation temperature increases, a dense Al₂O₃ protective film forms on its surface, significantly enhancing its oxidation resistance. Beyond 1000 ℃, this Al₂O₃ film fractures, leading to transformation of the primary phases into Fe₂O₃, Al₄B₂O₉ and amorphous B₂O₃. Within the oxidation temperature range of 300-800 ℃, the wave absorption performance of the sample progressively improves with increasing oxidation temperature, exhibiting particularly outstanding dielectric loss capabilities around 10 GHz. At an oxidation temperature of 900 ℃, the sample achieves a reflection loss of -42.60 dB at a frequency of 11.28 GHz, with corresponding a thickness of 2.8 mm. The Al₂O₃ film significantly enhances dielectric loss efficiency by inducing interfacial polarization loss at the "oxide film-matrix" interface. This study elucidates that oxidation mechanisms of Fe₂AlB₂ at varying temperatures and examines consequent impacts on wave-absorbing properties, thereby providing a theoretical foundation for its application in high-temperature wave-absorbing environments.

Ultra-high temperature oxide ceramics, known for their outstanding high-temperature strength, microstructural stability, oxidation and corrosion resistance, are anticipated to serve as the next generation of ultra-high temperature structural materials, suitable for prolonged use in high-temperature oxidizing environments, and are expected to have broad application potential in the aerospace sector. In recent years, laser additive manufacturing (LAM) technology has emerged as a prominent method for the preparation of ultra-high temperature oxide ceramics, characterized by advantages such as rapid near-net shaping, mold-free production, and high flexibility for fabricating complex-shaped parts, thereby establishing itself as a significant research hotspot. However, ceramics are highly prone to pore defects during LAM process, which not only hinders the subsequent deposition of samples but also leads to deterioration in the surface quality and mechanical properties of formed parts. This review firstly provides an overview of the basic principles and process characteristics of three LAM techniques, including selective laser sintering (SLS), laser powder bed fusion (LPBF), and laser directed energy deposition (LDED). It focuses on characteristics of pore defects, flow characteristics of molten pool, and formation mechanism of pore defects in the LAM of ultra-high temperature oxide ceramics. Furthermore, their research progress in suppressing pore defects is detailed from three aspects: optimization of process parameters, outfield assistance, and second-phase doping. Finally, their challenges associated with achieving practical engineering applications are summarized, along with prospective development trends and breakthrough points in the field, focusing on suppression of forming defects, powder characteristics and subsequent heat treatment.

Driven by global energy transition and carbon neutrality goals, proton-conducting solid oxide fuel cells (P-SOFCs) have become a research hotspot in clean energy technology due to their advantages of efficient medium-to-low temperature power generation (400-600 ℃), excellent fuel compatibility, and high energy conversion efficiency. This review analyzes the development prospects of hydrogen-containing fuel P-SOFCs. Addressing key technological bottlenecks, this review focuses on three core dimensions including material design, reaction mechanisms, and characterization techniques to summarize research progress and technical challenges in hydrocarbon-fueled and ammonia-fueled P-SOFC systems. For hydrocarbon-fueled P-SOFCs, the carbon deposition issue is thoroughly examined. Their formation mechanisms, characterization methods and influencing factors on carbon deposition are discussed in depth. Advanced improvement strategies are highlighted, including modification of reforming catalysts, optimization of proton-conducting electrolytes, and novel design of electrodes. Regarding direct ammonia fuel cells (DAFCs), challenges related to insufficient anode durability are addressed. Critical influencing factors are identified as catalyst activity, support types, nitridation corrosion mechanisms, hydrogen partial pressure, ammonia flow rate, and anode microstructure. Based on cutting-edge research, novel improvement strategies, such as anode modification, optimization of anode catalytic layers and innovative cell structure designs, are summarized. This review outlines future development directions to advance the commercialization of hydrogen-containing fuel P-SOFCs.