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.

Violet light excited white light emitting diodes (LEDs) have attracted widespread attention due to their advantages of tunable color temperature and visual comfort. However, high-performance phosphors suitable for violet light excitation (400-420 nm) have not yet been widely applied on a large scale. One of the key factors regarding the commercial utilizations is the stability. Unfortunately, there still lacks research on this issue. In this study, three rare-earth phosphors suitable for violet light excitation in LEDs were synthesized via a solid-state reaction method, namely K₂CaPO₄F:Eu²⁺, K_1.3Al₁₁O_17+δ:Eu²⁺ and Ca₂YHf₂Al₃O₁₂:Ce³⁺,Tb³⁺. The stability experiments were then conducted under conditions of high temperature and humidity, water immersion, and long-term violet light irradiation from LED chips. The luminescent properties, failure mechanisms, and environmental stability were analyzed. Finally, a white LED device was prepared by combining the as-synthesized three phosphors onto a 400 nm violet light chip. Results demonstrate that the as-synthesized phosphors exhibit not only optimized luminescence performance compared to phosphors prepared in former works, but also a more comprehensive evaluation of environmental stability across different conditions. The white LED device achieves a color rendering index of 93.6, a correlated color temperature of 5151 K and a color coordinate of (0.34, 0.36), showcasing excellent white light illumination performance. Furthermore, the environmental stability of the white LED device is improved compared to individual phosphors. By taking lead in investigating the environmental stability of violet light excited LED phosphors, this work provides valuable insights and guidance for advancing their applications.

As an essential candidate for environment-friendly luminescent quantum dots (QDs), CuInS-based QDs have attracted more attention in recent years. However, several drawbacks still hamper their industrial applications, such as lower photoluminescence quantum yield (PLQY), complex synthetic pathways, uncontrollable emission spectra, and insufficient photostability. In this study, CuInZnS@ZnS core/shell QDs was prepared via a one-pot/three-step synthetic scheme with accurate and tunable control of PL spectra. Then their ensemble spectroscopic properties during nucleation formation, alloying, and ZnS shell growth processes were systematically investigated. PL peaks of these QDs can be precisely manipulated from 530 to 850 nm by controlling the stoichiometric ratio of Cu/In, Zn²⁺ doping and ZnS shell growth. In particular, CuInZnS@ZnS QDs possess a significantly long emission lifetime (up to 750 ns), high PLQY (up to 85%), and excellent crystallinity. Their spectroscopic evolution is well validated by Cu-deficient related intragap emission model. By controlling the stoichiometric ratio of Cu/In, two distinct Cu-deficient related emission pathways are established based on the differing oxidation states of Cu defects. Therefore, this work provides deeper insights for fabricating high luminescent ternary or quaternary-alloyed QDs.

To further expand the application of advanced ceramic materials in helicopters, this paper reviews their application in helicopter structures both domestically and internationally. It emphasizes the technical maturity and development trends of various ceramic materials in helicopter specific structural applications, such as energy impact protection parts, energy conversion components, and corrosion protection areas. By comparing the gaps between domestic and international use of advanced ceramic materials in helicopter specific structures, the paper provides suggestions for the future development. Recommendations include the use of reaction-sintered contoured integrated opaque armor ceramics and polycrystalline transparent armor ceramics for the high-speed dynamic impact energy protection parts, cermet composite coatings compatible with epoxy resin composite substrates for the low-energy impact protection parts, and hybrid ceramic matrix composite/polymer matrix composite (HCMC-PMC) materials for the thermal shock protection parts. Additionally, multifunctional composite materials, such as high-performance miniature piezoelectric ceramic thin film functional devices and flexible hybrid electronic structures based on micro-piezoelectric ceramic materials, should be developed for the mechanical and electrical energy conversion components. Microwave-absorbing ceramic composites derived from polymer-derived ceramics that are compatible with epoxy resin composite substrates are recommended for the electromagnetic and thermal energy conversion components. Furthermore, high-performance abrasion-resistant and corrosion-resistant Sol-Gel coatings are suggested for the corrosion protection areas. It is also essential to establish a high-speed dynamic energy impact protection mechanism for helicopters, optimize the ballistic performance of protective materials, and develop advanced ceramic materials digital testing and verification technologies, represented by multi-functional composite materials for helicopter specific structures. These efforts will greatly shorten the application cycle of advanced ceramic materials and reduce the verification cost.

SiC ceramics exhibit high strength and thermal stability, rendering them highly suitable for applications in space and thermal components. However, the growing demand for large-sized and complex-shaped SiC ceramics necessitates advanced manufacturing techniques. In comparison to traditional reduction and equal material manufacturing methods, 3D printing technology offers significant advantages in various aspects, such as manufacturing cycle, effective cost, and reliability. There are many 3D printing methods, each with distinct characteristics. Stereolithography (SLA) is capable of achieving high precision and superior surface quality. However, its practical applications often necessitate special design of support structures. Additionally, issues such as residual stress and low solid content significantly hinder its further development. Selective laser sintering (SLS) exhibits strong material compatibility, which is suitable for a wide range of materials, including polymers, metals and ceramics. This technology enables large-scale rapid prototyping at low manufacturing costs. But its surface quality of the formed billet is typically insufficient, which needs additional post-processing. Fused deposition modeling (FDM) though facilitates the preparation of SiC ceramics via reaction sintering, proves unsuitable for constructing large components which restricts its applicability in actual production contexts, due to its inadequate interlayer bonding strength coupled with pronounced surface striations and slower forming speeds. This paper reviews the latest research progresses of 3D-printed SiC ceramics and analyzes the subsequent high-temperature densification treatments of green bodies, along with their fundamental physical properties. Finally, it proposes some prospects of 3D printing of SiC ceramic materials, and strengthens integration of new 3D printing technologies and various printing methods for fine regulation of ceramics’ macro- and micro-structures.

Inorganic non-metallic biomaterial is one of main types of biomaterials, which is widely used in biomedical fields such as tissue repair, tumor therapy, and drug delivery., making an important contribution to national life and health. Research on inorganic non-metallic biomaterials in China is flourishing, but their production and application are still in the stage of overcoming difficulties. To realize the high-quality development of China's inorganic non-metallic biomaterials and improve their hard power to protect national life and health, this paper analyzes hotspots and difficult problems in research and application of China's inorganic non-metallic biomaterials by means of strategic study. Based on current development opportunities and challenges, some suggestions are proposed for the development of inorganic non-metallic biomaterials, such as material design for unique performance, research on materiobiology, exploration of new principles and mechanisms mediated by materials, customization by intelligent personalization, design through big data screening and artificial intelligence, and standardization based evaluation/regulation. This aims to provide guidance for development of inorganic non-metallic biomedical products and push forward scientific research while accumulating talent resources.

Compared with traditional lithium-ion batteries, sodium-ion batteries are an ideal alternative due to their cost advantages and sustainable resource supply. At present, the cathode materials for sodium-ion batteries mainly include transition metal oxides, polyanionic compounds and Prussian blue analogues. However, irreversible phase conversion, Jahn-Teller effect and interface instability of cathode materials seriously affect the cycling stability of sodium-ion batteries. In this paper, the research progress and industrialization process of strategies for improving cyclic stability of cathode materials for sodium-ion batteries are systematically introduced. Firstly, the structure as well as advantages and disadvantages of cathode materials is analyzed in detail, and the structural stability, cost and cycling performance are compared. Secondly, the latest research progress of structure optimization and chemical element doping strategies in improving the cycling stability of cathode materials is elaborated in detail, and the interaction between structural stability, electronic conductivity, ion intercalation/deintercalation of cathode materials and electrochemical performance is revealed. Then, the development process and industrialization progress of sodium-ion batteries are summarized. Finally, the significant problems that still need to be addressed for cathode materials and systems for sodium-ion batteries are sorted out and their future developments are prospected, aiming to propel the steady and healthy development of sodium-ion battery industry.

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.

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.

Development of novel artificial synaptic devices, which make up the majority of neural networks, has emerged as a pivotal path to hardware realization of neuromorphic computing. An electrochemical ion synapse, also known as a three-terminal synaptic device based on electrochemical transistors, is a device that may efficiently use ions in the electrolyte layer to modify channel conductivity. By electrochemical doping and recovering ions in channel materials exhibiting redox activity, this device mimics biological synaptic properties. The advantages of the electrochemical ion synapse, which uses proton (H⁺) as the doping particle, are lower energy consumption, faster operation, and a longer cycle life among the ions that alter the channel material's conductance. This article reviews the recent research progress on proton-regulated electrochemical ion synapses, summarizes the material systems used for the channel layer and electrolyte layer of proton-regulated electrochemical ion synapses, analyzes the challenges faced by proton-regulated electrochemical ion synapses, and points out directions on their future development.

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.

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.

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.

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.

High-entropy carbide (HEC) ceramics are distinguished by their high hardness, oxidation resistance, corrosion resistance, wear resistance, and high thermal conductivity, positioning them as promising candidates for application in extreme environments. However, inherent brittleness of these high-entropy ceramics limits their further application. In order to enhance the toughness of HEC ceramics, polycarbosilane (PCS), a precursor of silicon carbide (SiC), was added into the precursor of (Zr, Hf, Nb, Ta, W)C high-entropy ceramic. The in-situ formed SiC (SiC_i) by pyrolysis of PCS can serve as reinforcement for HEC ceramics. The results demonstrate that the volume fraction of SiC in the ceramics obtained from the pyrolysis of PCS is 23.38%. The SiC phases, with an average grain size of 1.19 μm, are evenly distributed in the high-entropy ceramic matrix. The pyrolysis process of ceramic precursors was investigated, revealing that the pyrolysis products of PCS exit as amorphous O_x-Si-C_y at low pyrolysis temperature, while a crystalline SiC phase emerges when the pyrolysis temperature exceeds 1500 ℃. Bulk (Zr, Hf, Nb, Ta, W)C-SiC_i ceramic was prepared by hot-pressing of precursor-derived ceramic powders obtained through pyrolysis at 1600 ℃. Mechanical properties of (Zr, Hf, Nb, Ta, W)C-SiC_i ceramic bulk were investigated, and composite ceramic bulks toughened by commercial silicon carbide nanopowders or silicon carbide whiskers were also prepared for comparison. Compared with (Zr, Hf, Nb, Ta, W)C ceramic, all composite ceramic bulks exhibit enhanced flexural strength and toughness. Notably, the in-situ generated SiC_i via precursor-derived method shows the most significant toughening effect. Flexural strength and fracture toughness of (Zr, Hf, Nb, Ta, W)C-SiC_i ceramic are (698±9) MPa and (7.9±0.6) MPa·m^1/2, respectively, representing improvements of 17.71% and 41.07% compared to that of (Zr, Hf, Nb, Ta, W)C ceramic bulk. Taking all above data into comprehensive account, the improvement is mainly due to the small grain size and uniform distribution of SiC in the composite ceramics prepared via precursor-derived method, which enhance energy consumption and hinder crack propagation under external stress.

Inorganic nanoparticles have demonstrated significant applications in biomedicine field, whose biomedical functions and physicochemical properties are greatly influenced by their size and morphology. However, it still remains challenging to achieve high batch-to-batch reproducibility in the synthesis of inorganic nanoparticles with traditional batch synthesis methods. Meanwhile, microfluidic technology offers an advanced strategy that provides high controllability and repeatability for the synthesis of inorganic nanoparticles. Additionally, it facilitates rapid mass and heat transfer, while offering the advantages of small reaction volumes and low energy consumption, rendering it an ideal approach for the synthesis of inorganic nano-biomaterials. This article reviews the research and application progress of microfluidic technology in preparation of inorganic nano-biomaterials. Firstly, flow regimes and principles of mixing in the microfluidic devices are introduced. Subsequently, structural features and fluid mixing efficiency of five widely studied and applied microfluidic devices are presented. Importantly, applications of these microfluidic devices in synthesis and surface modification of inorganic nanoparticles are comprehensively summarized. Finally, this article briefly outlines challenges and potential opportunities for future developments in microfluidic-based synthesis and application of inorganic nano-biomaterials.

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.

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.

Methane pyrolysis is a technology that utilizes fossil energy to produce high added value carbon materials and hydrogen. However, traditional methods, such as chemical vapor deposition (CVD) and molten metal catalysis, face challenges in the production of graphene, including catalyst deactivation, difficulty in separating graphene from the catalyst, and high reaction temperatures (≥1100 ℃), which limit their industrial applications. This study proposes an innovative approach to produce graphene by catalyzing methane pyrolysis using Cu and metal oxides-KCl molten medium. By adding metal oxides (Al₂O₃, TiO₂, ZrO₂, MgO, SiO₂) as dispersants, the dispersion of active Cu sites is enhanced. Notably, Cu/ZrO₂ with a Cu content of 50% (in volume) and Cu/MgO with a Cu content of 75% (in volume) catalysts enable the efficient production of few-layer graphene. Cu/ZrO₂ catalyst with a Cu content of 50% (in volume) exhibits the highest activity, achieving a methane conversion rate of 22%, a hydrogen production yield of 21.5 mmol/h, and formation of large-area and smooth few-layer graphene. This study provides a new technical route for co-production of graphene and hydrogen via methane pyrolysis, offering potential for large-scale graphene production in the future.

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.

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.

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.

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.

Metal phosphides have been studied as prospective anode materials for sodium-ion batteries (SIBs) due to their higher specific capacity compared to other anode materials. However, rapid capacity decay and limited cycle life caused by volume expansion and low electrical conductivity of phosphides in SIBs remain still unsolved. To address these issues, GeP₃ was first prepared by high-energy ball milling, and then Ketjen black (KB) was introduced to synthesize composite GeP₃/KB anode materials under controlled milling speed and time by a secondary ball milling process. During the ball milling process, GeP₃ and KB form strong chemical bonds, resulting in a closely bonded composite. Consequently, the GeP₃/KB anodes was demonstrated excellent sodium storage performance, achieving a high reversible capacity of 933.41 mAh·g^-1 at a current density of 0.05 A·g^-1 for a special formula of GeP₃/KB-600-40 sample prepared at ball milling speed of 600 r/min for 40 h. Even at a high current density of 2 A·g^-1 over 200 cycles, the capacity remains 314.52 mAh·g^-1 with a retention rate of 66.6%. In conclusion, this work successfully prepares GeP₃/KB anode-carbon composite for electrodes by high-energy ball milling, which can restrict electrode volume expansion, enhance capacity, and improve cycle stability of SIBs.

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.

SiC/SiC composites have emerged as essential thermal structure materials for development of hypersonic vehicles and high thrust-to-weight ratio aero-engines. Design and utilization of boron-containing ceramic precursors as impregnation agents for precursor infiltration and pyrolysis (PIP) to introduce self-healing components into matrix represent a key strategy for enhancing the antioxidant properties of SiC/SiC composites. Here, borane pyridine or borane triethylamine were utilized as boron sources and subsequently mixed with a solid polycarbosilane (PCS) xylene solution to prepare different boron-modified PCS solutions. These solutions were used as PIP impregnation agents to fabricate various boron-modified SiC/PyC (pyrolytic carbon)/SiC composites. The physicochemical properties of boron-modified PCS-derived ceramics, along with the physical and mechanical properties of SiC/PyC/SiC composites before and after matrix boron modification, were investigated. Results demonstrated that addition of appropriate amounts of borane pyridine and borane triethylamine as boron sources in solid PCS solutions effectively introduced boron as a heterogeneous element into the derived SiC ceramics. Compared to PCS, the boron-modified PCS solutions (BP-1 and BP-2) exhibited increased ceramic yields. The derived ceramics exhibited a semi-crystalline β-SiC structure, with boron element contents of 1.7% and 2.2% (in mass), respectively. In contrast to unmodified composite, the boron-modified SiC/SiC composites exhibited negligible changes in density, apparent porosity, and fracture toughness. However, the flexural modulus increased from 116 GPa to 132 GPa. Furthermore, the flexural strength of the modified composite using borane pyridine alone as boron source was 658 MPa, comparable to the unmodified composite's strength of 643 MPa, but with a reduced dispersion coefficient. All above data demonstrate that borane pyridine can be used as boron source for preparation of boron-modified SiC/SiC composites, providing valuable insights for developing high-performance SiC/SiC composite hot-end components.

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.

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.

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.

The accepted doping ion in Ti⁴⁺-site of PbZr_yTi_1-yO₃ (PZT)-based piezoelectric ceramics is a well-known method to increase mechanical quality factor (Q_m), since the acceptor coupled by oxygen vacancy becomes defect dipole, which prevents the domain rotation. In this field, a serious problem is that generally, Q_m decreases as the temperature (T) increases, since the oxygen vacancies are decoupled from the defect dipoles. In this work, Q_m of Pb_0.95Sr_0.05(Zr_0.53Ti_0.47)O₃ (PSZT) ceramics doped by 0.40% Fe₂O₃ (in mole) abnormally increases as T increases, of which the Q_m and piezoelectric coefficient (d₃₃) at room temperature and Curie temperature (T_C) are 507, 292 pC/N, and 345 ℃, respectively. The maximum Q_m of 824 was achieved in the range of 120-160 ℃, which is 62.52% higher than that at room temperature, while the dynamic piezoelectric constant (d₃₁) was just slightly decreased by 3.85%. X-ray diffraction (XRD) and piezoresponse force microscopy results show that the interplanar spacing and the fine domains form as temperature increases, and the thermally stimulated depolarization current shows that the defect dipoles are stable even the temperature up to 240 ℃. It can be deduced that the aggregation of oxygen vacancies near the fine domains and defect dipole can be stable up to 240 ℃, which pins domain rotation, resulting in the enhanced Q_m with the increasing temperature. These results give a potential path to design high Q_m at high temperature.

The lithium-based silicate microwave dielectric ceramics with ultra-low permittivity show great potential as substrate materials in the fifth-generation wireless communication technology. However, the residual stress caused by higher sintering temperatures leads to increased dielectric loss, thereby deteriorating the microwave dielectric performance. In this work, B³⁺ was introduced into LiAlSi₂O₆ ceramics to reduce Al³⁺ content, aiming to improve their sintering temperature and microwave dielectric performance. LiB_xAl_1-xSi₂O₆ (0≤x≤0.20) microwave dielectric ceramics were prepared using a combination of solid-state reaction and cold isostatic pressing techniques. Effects of B³⁺ doping on the sintering characteristics, phase structure, microstructure, and microwave dielectric properties of the materials were characterized. The results show that with a gradual increase in the doping concentration, sintering temperature of the ceramics decreases significantly from 1400 to 1000 ℃. Meanwhile, the relative permittivity (ε_r) decreases from 3.95 to 3.69, the quality factor (Q×f) increases significantly from 24300 to 30560 GHz, and the temperature coefficient of resonant frequency (τ_f) increases from -45.9×10^-6 to -20.9×10^-6 ℃^-1. Specifically, the change in ε_r is mainly influenced by intrinsic polarization, lattice vibrations, and covalent bond strength of the material; the improvement in Q×f is closely related to the increase in packing fraction (PF) and the decrease in damping coefficient; the increase in τ_f is strongly correlated with the bond valence of oxygen (V_O). Furthermore, the composition with x = 0.20 exhibits the best microwave dielectric performance with ε_r = 3.69, Q×f = 30560 GHz, and τ_f = -20.9×10^-6 ℃^-1. Findings of this study on LiB_xAl_1-xSi₂O₆ provide important theoretical guidance and practical insights for development and application of high-performance microwave dielectric ceramics in the future.

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.

Nano-hydroxyapatite (nHAP) possesses both biocompatibility and environmental friendliness, and holds the potential to become a novel ultraviolet (UV) absorbent material following iron doping modification. This study employed co-precipitation and hydrothermal methods to prepare iron-doped nano-hydroxyapatite (Fe-nHAP). Influence of the preparation process on UV absorption performance was investigated by adjusting reaction time, temperature, and iron doping ratio. The results indicate that with the increase of temperature from 37 ℃ to 150 ℃ or the extension of reaction time from 0.5 h to 3 h, both the crystallinity and the peak of UV absorption improve. It can be inferred that there is a certain positive correlation between the UV absorption performance and crystallinity of Fe-nHAP. Additionally, the UV absorption capacity is closely correlated to the iron doping ratio. As the iron doping molar ratio increases from 0 to 10%, the UV absorption capacity is gradually enhanced, with the maximum absorption value rising from 0.03 to 1.35. This phenomenon is attributed to the reduction in optical bandgap caused by iron doping. However, a high iron doping ratio leads to excessive reduction in material crystallinity, resulting in weakened enhancement of UV absorption performance. The safety assessment indicates that Fe-nHAP with an iron doping molar ratio of 7% does not demonstrate cytotoxicity, phototoxicity and skin irritation. In summary, Fe-nHAP has a suitable UV absorption performance. With its favorable biosecurity, it is anticipated to emerge as a new type of UV absorption material.

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.

With the rapid development of new aerospace vehicles, there are increasing demands for higher structural reliability and wideband microwave stealth requirements for the components operating under high-temperature condition. SiBCN based metastable ceramics exhibit good resistance to high temperature, thermal shock, ablation, long-term oxidation, and creep, showcasing great potential in the field of high-temperature structural microwave absorption. However, their ability to absorb electromagnetic waves is limited by low dielectric loss. In this study, the SiBCN-rGO ceramic fibers with good mechanical and microwave-absorbing properties were prepared using the wet spinning technology. Results showed that the as-prepared SiBCN-rGO ceramic fibers possessed porous structure, with porosity increasing with the increase of reduced graphene oxide (rGO) content. Additionally, both high rGO content and high fiber specific surface area promoted the crystallization of SiC within the amorphous matrix. The introduction of rGO significantly enhanced the tensile properties of the resulting ceramic fibers. As the mass fraction of rGO increased from 0 to 4%, the fibers’ elongation at break increased from 8.05% to 18.05%, and the tensile strength increased from 1.62 cN/dtex (0.324 GPa) to 2.32 cN/dtex (0.464 GPa). The increase of rGO content also reduced the electrical resistivity of the ceramic fibers. Moreover, as the rGO mass fraction increased from 0 to 4%, both the real and imaginary parts of the fibers’ dielectric constant decreased, while the loss tangent gradually increased. The SiBCN-rGO ceramic fibers with those containing 6% (mass fraction) rGO exhibited excellent wave-absorption performance, showing the minimum reflection coefficient of -50.90 dB at 9.20 GHz and an effective absorption bandwidth of 2.3 GHz, indicating promising applications in wave-absorbing ceramic matrix composites.

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.

The development of low-cost and long-lifespan sodium-ion battery (SIB) cathode materials is crucial for large-scale energy storage. Iron-based phosphate cathode materials have attracted significant attention in recent years for their high theoretical capacity, excellent structural stability and rich resources. Here, a series of Na₄Fe_xP₄O_12+x/C (x=2.6-3.3) electrode materials are prepared using Sol-Gel technique and thermal treatment process. Effect of the phase structure on electrochemical performance of Na₄Fe_xP₄O_12+x/C electrode materials is investigated. It is found that three phases, including Na₂FeP₂O₇ (NFPO), Na₄Fe₃(PO₄)₂P₂O₇ (NFPP) and NaFePO₄ (NFP), mainly exist in the Na₄Fe_xP₄O_12+x/C system. Among Na₄Fe_xP₄O_12+x/C electrode materials, Na₄Fe_3.1P₄O_15.1/C electrode material with the highest content of NFPP phase possesses rapid electronic and sodium-ion conduction characteristics, thereby exhibiting the optimal electrochemical performance. As a result, the SIB equipped with Na₄Fe_3.1P₄O_15.1/C electrode material shows high reversible capacity, with a discharge specific capacity of 102.8 mAh·g^-1 at a current density of 0.1C (1C=129 mAh·g^-1), as well as capacity retention of 88.7% after 700 cycles. Furthermore, the as-assembled battery exhibits excellent rate performance with a discharge specific capacity of 61.5 mAh·g^-1 at a current density of 5C.

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.