In response to the evolving landscape of high-speed aircraft, characterized by an expansive airspace, prolonged flight durations, and increased velocities, the thermal protection requirements for key structures such as the nose cone, leading edge, and engine combustion chamber have become more exacting. This necessitates a concerted focus on the development of high-performance thermal protection materials capable of withstanding extreme conditions. Ultra-high temperature ceramic composites have emerged as noteworthy candidates, showcasing exceptional oxidation and ablation resistance. Despite their commendable properties, the inherent brittleness of these composites poses a significant obstacle to widespread engineering applications. To address this limitation, there is a growing emphasis on toughening through structural modulation. Simultaneously, the imperative to enhance aircraft payload capacity underscores the demand for lightweight ultra-high temperature ceramic composites. This paper provides a systematic overview of the major research advances made in recent years on ultra-high temperature ceramic composites, including preparation methods such as pressure sintering, slurry infiltration, precursor impregnation and pyrolysis, reactive melt infiltration, chemical vapor infiltration/deposition, and “solid-liquid” combination process, toughening methods such as particles, whiskers, soft-phase materials, short-cut fibers, and continuous fibers, as well as oxidation ablation resistant properities and mechanisms, and lightweighting design. The relationship between the components, microstructures and properties of ultra-high temperature ceramic composites is discussed in depth, and the current challenges as well as the future development trends of ultra-high temperature ceramic composites are presented.

The development of high-speed flight technology has put forward an urgent demand for high- performance thermal structure materials. High-entropy carbides (HECs) ceramics are a fast-emerging family of materials that combine the excellent properties of high-entropy ceramics and ultra-high temperature ceramics. HECs have a broad application prospect in extreme service environments, which has received extensive attention from scholars in recent years. Compared with traditional ultra-high temperature carbides containing only one or two transition metal elements, HECs have a greater potential for development because of their improved comprehensive performance and greater designability of composition and properties. After successive exploration of HECs in recent years, researchers have obtained many interesting results, developed a variety of preparation methods, and gained comprehensive understanding of microstructure and properties. The basic theories and the laws on HECs obtained from experimental process are reviewed in this paper. Preparation methods of HECs including powders, blocks, coatings and films, as well as fiber-reinforced HECs-based composites are summarized. Research progress on the properties of HECs, such as the mechanical properties, thermal properties, and especially the oxidation and ablation resistance related to high-temperature applications, is reviewed and discussed. Finally, the scientific issues that need to be further explored in this area are emphasized, and the prospects are proposed.

Recently, organic-inorganic hybrid perovskite solar cells have demonstrated a broad commercial prospect due to their high photoelectric conversion efficiency (PCE) and low fabricating costs. During the past decades, the highest reported PCE of small-area (<1 cm²) perovskite solar cells (PSCs) rose to 26.10%, and those of large-area (1-10 cm²), mini-module level (10-800 cm²) and module level (>800 cm²) PSCs increased to 24.35%, 22.40% and 18.60%, respectively. The performance of PSCs decreases dramatically with the area increasing due to limitation of the deposition method and the poor quality of large-area perovskite films. Spin-coating method is not suitable for actual industrial production, while the scalable deposition methods including blade-coating and slot-die coating still face the difficulty of precisely controlling nucleation and crystallization of the perovskite films with large area. This review summarized preparation methods of large-area perovskite films, and discussed the film-forming mechanism and strategies for high-quality perovskite films. Finally, relevant outlooks on technologies and applications for large-area PSCs with high performances and stabilities were analyzed. This review is expected to provide insights on the research of large-area PSCs with high performance.

Developing novel low-dimensional materials for terahertz electromagnetic shielding and absorbing applications represents a critical research frontier. Their unique electrical, mechanical, and electromagnetic responses hold great potential in enabling more efficient solutions for electromagnetic shielding and absorbing. Two-dimensional transition metal carbides, nitrides, and carbonitride MXenes have already demonstrated excellent electromagnetic shielding and absorbing performance in the low-frequency spectrum. MXenes possess high conductivity, low density, and high flexibility, which are advantageous for future portability and integration of terahertz devices and systems. However, practical implementation of MXene-based terahertz electromagnetic shielding and absorption materials faces challenges in adhesion stability, environmental resilience, and high-temperature tolerance, hindering their suitability for aerospace and future next generation communication applications. Moreover, in terahertz frequency band, lacking more comprehensive and reliable electromagnetic scattering and absorbing measurement methods limits the development of THz shielding and absorbing materials. Extensive research efforts have targeted on these limitations, exploring fundamental architectural and theoretical aspects of prevalent electromagnetic materials. This review specifically highlights the terahertz electromagnetic shielding and absorption characteristics inherent in various MXenes and their compositions, such as Ti₃C₂T_x, Mo₂Ti₂C₃T_x, Mo₂TiC₂T_x, Nb₄C₃T_x, and Nb₂CT_x. Additionally, this review envisages the forthcoming challenges and prospects of MXenes as a pivotal electromagnetic shielding and absorbing material within the terahertz frequency band.

Inspired by gene scissor concept in biological genetic engineering, chemical scissors, as important research tools, play an important role in the study of structure editing and application of materials. We aim to review the research progress of chemical scissors in structural editing and applications of materials. First of all, we introduce the basic concept and mechanism. Chemical scissors strategy refers to a methodology for material editing through which the main crystal structure is preserved but targeted atoms or structural units are knocked out, replaced, repaired or reconstructed in order to realize special functionality. Subsequently, the specific applications of chemical scissors in materials structure editing are discussed in depth, including the methods and functional designs for precise structure modulation of materials by chemical shearing, modification, synthesis, as well as etching and intercalation. Finally, the future research direction of chemical scissors in the field of material structure editing is envisioned, including developing new chemical scissors that are more intelligent and efficient, exploring more innovative strategies for material structure editing, understanding the underlying chemical mechanism, and further expanding the applicability of chemical scissors. Overall, we summarize the research progress and potential of material structural editing, which provides important theoretical and experimental support for further exploring and developing the application of chemical scissors in the field of materials.

Nowadays, artificial intelligence (AI) is playing an increasingly important role in human society. Running AI algorithms represented by deep learning places great demands on computational power of hardware. However, with Moore's Law approaching physical limitations, the traditional Von Neumann computing architecture cannot meet the urgent demand for promoting hardware computational power. The brain-inspired neuromorphic computing (NC) employing an integrated processing-memory architecture is expected to provide an important hardware basis for developing novel AI technologies with low energy consumption and high computational power. Under this conception, artificial neurons and synapses, as the core components of NC systems, have become a research hotspot. This paper aims to provide a comprehensive review on the development of oxide neuron devices. Firstly, several mathematical models of neurons are described. Then, recent progress of Hodgkin-Huxley neurons, leaky integrate-and-fire neurons and oscillatory neurons based on oxide electronic devices is introduced in detail. The effects of device structures and working mechanisms on neuronal performance are systematically analyzed. Next, the hardware implementation of spiking neural networks and oscillatory neural networks based on oxide artificial neurons is demonstrated. Finally, the challenges of oxide neuron devices, arrays and networks, as well as prospect for their applications are pointed out.

Smart windows have gained tremendous attention because of their ability to dynamically modulate the solar radiation to minimize energy consumption and improve indoor living comfort. Vanadium dioxide (VO₂) is one of the most attractive thermochromic materials for energy-saving smart windows due to its reversible metal-to-insulator transition at a critical temperature of ~68 ℃ and accompanying great change of its optical transmittance. However, VO₂ itself has a couple of significant limitations as a smart window material: high phase transition temperature (τ_c), low luminous transmittance (T_lum) and insufficient solar energy modulation ability (ΔT_sol). Several methods have been used to grow VO₂ thin films with improved properties to meet the specific requirements for smart windows applications. The phase transition temperature (τ_c) should be reduced to near room temperature, in the meantime luminous transmittance (T_lum) and solar energy modulation ability (ΔT_sol) should be high enough for the modulation of indoor temperature self-adapted to seasons and climate. The most common way to reduce τ_c is by doping. To enhance T_lum and ΔT_sol, multilayer structures and/or nanocomposite film have been widely adopted. Chemical vapor deposition (CVD) is a promising technique to produce high quality and highly uniform VO₂ thin film with different morphologies in large scale and at low costs. In this paper, various CVD techniques, such as atmospheric pressure chemical vapor deposition (APCVD), aerosol-assisted chemical vapor deposition (AACVD), low-pressure chemical vapor deposition (LPCVD), metal-organic chemical vapor deposition (MOCVD), atomic layer deposition (ALD) and plasma-enhanced chemical vapor deposition (PECVD), are examined with respect to their advantages for VO₂ deposition, film quality and the strategies for film quality improvement. Finally, challenges and opportunities for further research and development of VO₂ thermochromic films using PECVD technique are emphasized.

Semiconductor materials are the core of modern technology development and industrial innovation, with high frequency, high pressure, high temperature, high power, and other high properties under severe conditions or super properties needed by the “double carbon” goal, the new silicon carbide (SiC) and gallium nitride (GaN) as representative of the third generation of semiconductor materials gradually into industrial applications. For the third-generation semiconductor, there are several development directions in its packaging interconnection materials, including high-temperature solder, transient liquid phase bonding materials, conductive adhesives, and low-temperature sintered nano-Ag/Cu, of which nano-Cu, due to its excellent thermal conductivity, low-temperature sintering characteristics, and good processability, has become a new scheme for packaging interconnection, with low cost, high reliability, and scalability. Recently, the trend from material research to industrial chain end-use is pronounced. This review firstly introduces the development overview of semiconductor materials and summarizes the categories of third-generation semiconductor packaging interconnect materials. Then, combined with recent research results, it further focuses on the application of nano-Cu low-temperature sintering in electronic fields such as packaging and interconnection, mainly including the impact of particle size and morphology, surface treatment, and sintering process on the impact of nano-Cu sintered body conductivity and shear properties. Finally, it summarizes the current dilemmas and the difficulties, looking forward to the future development. This review provides a reference for the research on low-temperature sintered copper nanoparticles in the field of interconnect materials for the third-generation semiconductor.

The question of what qualities excellent medical bioceramics must possess to ensure satisfactory prognosis for bone healing and reconstruction remains a topic of great interest in both clinical and biomaterial sciences. Our team has been dedicated to researching medical bioceramics since the 1990s, involving basic scientific research, applied translational research, and clinical trials. Consequently, we have amassed a wealth of research and implementation experience. In this article, we aim to explore the subject of “Functional Bioadaptability in Medical Bioceramics”, specifically focusing on calcium phosphate-based materials. We summarized how to effectively combine bioadaptability with design and manufacturing of medical bioceramics in the background of orthopedic clinical application, with the following aspects of structural adaptability, degradative adaptability, mechanical adaptability, and application adaptability. Hopefully, some suggestions put forward can ultimately provide valuable insights and recommendations for the design, production, supervision, and application of the upcoming medical bioceramics.

Organic-inorganic hybrid perovskite solar cells (PSCs) have attracted widespread attention due to their high power conversion efficiency (PCE) and low manufacturing cost. Although the certified PCE has reached 25.8%, the stability of PSCs under high temperature, high humidity, and continuous light exposure is still significantly inferior to that of traditional cells, which hinders their commercialization. Developing and applying highly stable inorganic hole transport materials (HTMs) is currently one of the effective methods to solve the photo-thermal stability of devices, which can effectively shield water and oxygen from corroding the perovskite absorption layer, thereby avoiding the formation of ion migration channels. This paper outlines the approximate classification and photoelectric properties of inorganic HTMs, introduces relevant research progress, summarizes performance optimization strategies for inorganic HTMs devices, including element doping, additive engineering, and interface engineering, and finally prospects the future development directions. It is necessary to further study the microstructure of inorganic HTMs and their relationship with the performance of PSCs to achieve more efficient and stable PSCs.

With the rise of the third-generation wide-bandgap semiconductors represented by SiC and GaN, power electronic devices are developing rapidly towards high output power and high power density, putting forward higher performance requirements on ceramic substrate materials used for power module packaging. The conventional Al₂O₃ and AlN ceramics are inadequate for the new generation of power module packaging applications due to low thermal conductivity or poor mechanical properties. In comparison, the newly developed Si₃N₄ ceramics have become the most potential insulating heat dissipation substrate materials due to its excellent mechanical properties and high thermal conductivity. In recent years, researchers have made a series of breakthroughs in the preparation of high strength and high thermal conductivity Si₃N₄ ceramics by screening effective sintering additive systems and optimizing the sintering processes. Meanwhile, as the advancement of the engineering application of coppered Si₃N₄ ceramic substrate, the evaluation of its mechanical, thermal, and electrical properties has become a research hotspot. Starting from the factors affecting thermal conductivity of Si₃N₄ ceramics, this article reviews the domestic and international research work focused on sintering aids selection and sintering processes improvement to enhance the thermal conductivity of Si₃N₄ ceramics. In addition, the latest progress in the dielectric breakdown strength of Si₃N₄ ceramic substrates and the evaluation of properties after being coppered are also systematically summarized and introduced. Based on above progresses and faced challengies, the future development direction of high strength and high thermal conductivity Si₃N₄ ceramic substrates is prospected.

Ceramic-based porous structures not only inherit the excellent properties of dense ceramic materials such as high-temperature resistance, electrical insulation, and chemical stability, but also have unique advantages similar to porous structures, including low density, high specific surface area, and low thermal conductivity. They show great potential in various applications, such as thermal insulation, bone tissue engineering, filtration and pollutants removal, and electronic components. However, there still exist some challenges for shaping complex geometries on the macro- scale and adjusting pore morphologies on the micro- and nano-scale through the conventional preparation strategy of ceramic-based porous structures. In recent decades, researchers have been devoting themselves to developing novel manufacturing techniques for ceramic-based porous structures. The direct-ink-writing 3D printing, as one of the representative additive manufacturing technologies, has become a current research hotspot, rapidly developing a series of mature theories and innovative methodologies for fabricating porous structures. In this work, the conventional strategies and additive manufacturing strategies for obtaining porous structures were firstly summarized. The direct-write assembly processes of pore structures were further introduced in detail, mainly including pseudoplastic ink formulation, solidification strategy, drying, and post-treatment. Meanwhile, the feasibility of direct-ink-writing 3D printing technologies combined with conventional manufacturing strategies in constructing ceramic-based hierarchical pore structures was analyzed emphatically. The new perspectives, developments, and discoveries of direct-ink-writing 3D printing technologies were further summarized in the field of manufacturing complex ceramic-based porous structures. In addition, the developments and challenges in the future were prospected according to the actual application status.

Methane is the second greenhouse gas contributing greatly to global warming, about 80 times of CO₂. Considering background of global warming and atmospheric methane growth, to catalyze total oxidation of atmospheric methane is of great importance to mitigate greenhouse effects and slow this global warming. However, catalytic oxidation of methane has always been a big challenge due to its high structural stability. In this article, research progress in total oxidation of methane under thermal-, photo- and photothermal-catalysis was reviewed. High temperature in thermal catalysis increases the energy loss and accelerates the deactivation of catalysts speedingly. Therefore, development of catalysts that oxidize methane under moderate temperatures is the main research interests. Photocatalysis provides a way to eliminate methane at ambient conditions with the assistance of solar energy, but the reaction rates are lower than that in thermal catalysis. It is worth mentioning that photothermal catalysis, developed in recent years, can achieve efficiently catalytic total oxidation of methane under mild conditions, showing a high potential application prospect. This article reviews development of three modes of catalysis, analyzes their different reaction mechanisms, advantages and disadvantages under different reaction conditions. Finally, prospects and challenges of this catalytic total oxidation are pointed out, which is expected to provide references for future research on this field.

MAX/MAB phases are a series of non-van der Waals ternary layered ceramic materials with a hexagonal structure, rich in elemental composition and crystal structure, and embody physical properties of both ceramics and metals. They exhibit great potential for applications in extreme environments such as high temperature, strong corrosion, and irradiation. In recent years, two-dimensional (2D) materials derived from the MAX/MAB phase (MXene and MBene) have attracted enormous interest in the fields of materials physics and materials chemistry and become a new 2D van der Waals material after graphene and transition metal dichalcogenides. Therefore, structural modulation of MAX/MAB phase materials is essential for understanding the intrinsic properties of this broad class of layered ceramics and for investigating the functional properties of their derived structures. In this paper, we summarize new developments in MAX/MAB phases in recent years in terms of structural modulation, theoretical calculation, and fundamental application research and provide an outlook on the key challenges and prospects for the future development of these layered materials.

Since the beginning of the 21st century, the third generation wide band gap (E_g>2.3 eV) semiconductor materials represented by gallium nitride (GaN) and zinc oxide (ZnO) are becoming the core supporting materials for development of semiconductor industry. Due to difficult growth and high cost of GaN and ZnO single crystal, epitaxial technology is always used as the substrate materials to grow GaN and ZnO films. Therefore, it is crucial to find an ideal substrate material for the development of third generation semiconductor. Compared with traditional substrate materials, such as sapphire, 6H-SiC and GaAs, scandium magnesium aluminate (ScAlMgO₄) crystal, as a new self-peeling substrate material, has attracted much attention because of its small lattice mismatch rate (~1.4% and ~0.09%, respectively) and suitable thermal expansion coefficient with GaN and ZnO. In this paper, based on structure of ScAlMgO₄ crystal, the unique trigonal bipyramid coordination and natural superlattice structure, the basis for its thermal and electrical properties, are introduced in detail. In addition, the layered structure of ScAlMgO₄ crystal along the c-axis makes it self-peeling, which greatly reduces its preparation cost and has a good application prospect in the preparation of self-supported GaN films. However, the raw material of ScAlMgO₄ is difficult to synthesize, and the crystal growth method is single, mainly through the Czochralski method (Cz), and growing techniques now in China lag far behind that in Japan. Therefore, it is urgent to develop a new growth method of growing high quality and large size ScAlMgO₄ crystals to break the technical barriers.

Large-sized crystalline materials are the basic raw materials in semiconductors, lasers, and communications. Preparation of large-scale, high-quality crystalline materials has become a bottleneck restricting the development of related industries. Breaking through the preparation theory and technology of large-sized crystal materials is the key to obtaining high-quality large-sized crystals. Preparation process of crystal materials often undergoes nucleation and growth stages, including multiple processes at spatiotemporal scale: from atom/molecules, through clusters and nuclei, to bulk crystals. To further explore and accurately understand the crystal growth mechanism, we need intensively study the multiscale process,multi-scale in situ characterization techniques, and computational simulation methods. Among them, the latest in situ characterization methods for crystal growth includes optical microscopy, electron microscopy, vibration spectra, synchrotron radiation, neutron technology, and especially, machine learning method. Thus, the multi-scale computational simulation techniques for crystallization is introduced, for example, first principles calculation at atom/molecular scale, molecular dynamics simulation, Monte Carlo simulation, phase field simulation at mesoscopic scale, and finite element simulation at macroscopic scale. A single in situ characterization or simulation technique can only explore crystallization information over a specific time and space scale. To accurately and fully reflect the crystallization process, a combination of multi-scale methods is introduced. It can be speculated that the establishment of in situ characterization technology and computational simulation methods for the actual large-sized crystal growth environment will be the future development trend, which provides an important experimental and theoretical basis for developing crystallization theory and controlling crystal quality. Furthermore, it can be deduced that the combination of in situ characterization technology with machine learning and big data technology will be the trend for large-sized crystal growth.

Compared with the first and second generation semiconductor materials, the third generation semiconductor materials exhibit higher breakdown field strength, higher saturated electron drift velocity, outstanding thermal conductivity, and wider band gap, suitable for manufacturing of electronic devices with high frequency, high power, radiation resistance, corrosion resistant properties, optoelectronic devices and light emitting devices. As one of the representatives of the third generation of semiconductor materials, gallium nitride (GaN) is an ideal substrate material for preparing blue-green laser, radio frequency (RF) microwave and power electronic devices. It has broad application prospects in laser display, 5G communication, phased array radar, aerospace, etc. Hydride vapor phase epitaxy (HVPE) method is the most promising method for growth of GaN crystals due to its simple growth equipment, mild growth conditions and fast growth rate. Due to the widely used quartz reactors, unintentionally doped GaN obtained by HVPE method inevitably has donor impurities (Si and O). Therefore, the grown GaN shows n-type electrical properties, high carrier concentration and low conductivity, which limits its application in high-frequency and high-power devices. Currently, doping is the most common method to improve the electrical performance of semiconductor materials, through which different types of GaN single crystal substrates can be obtained with different dopants to improve their electrochemical characteristics and meet the different needs of market applications. In this article, the basic structure and properties of GaN semiconductor crystal material are introduced, and the recent progress of the high quality GaN crystals grown by HVPE method is reviewed; and the doping characteristics, dopant types, growth process and the influence of doped atoms on the electrical properties of GaN are introduced. Finally, the challenges and opportunities faced by the HVPE method to grow doped GaN crystals are briefly described, and the future developments in several directions are prospected.

Film capacitors are the core electronic components of modern power devices and electronic equipment. However, due to the low dielectric constant, it is difficult to obtain high energy storage density (effective energy storage density or discharged energy density) for present film capacitors, leading to a large device size and high application cost. To improve the energy storage density of film capacitors, a nanocomposite approach is an effective strategy via combining high dielectric constant of the ceramic nanoparticles with high breakdown strength of the polymer matrix. Nevertheless, for single-layer structure of 0-3 polymer/ceramic composites, the dielectric constant and breakdown strength are difficult to be effectively enhanced at the same time, which limits the further improvement of energy storage density. To solve this contradiction, researchers have combined the composite film with high dielectric constant and high breakdown strength in a superposition to prepare 2-2 type multilayer composite dielectrics, which can achieve synergistic regulation of polarization strength and breakdown strength to obtain high energy storage density. The optimization of electric field distribution and the synergistic regulation of dielectric constant and breakdown strength can be achieved through mesoscopic and microstructural modulation of multilayer composite dielectrics. In this paper, the research progress of multilayer polymer-based composite dielectrics including ceramic/polymer multilayer structure and all-organic polymer multilayer structure in recent years is reviewed. Effect of multi-layer structure control strategy on the improvement of energy storage performance is emphasized. Moreover, enhancement mechanism of energy storage performance of polymer-based multilayer structure composite dielectric is summarized. Finally, challenges and development directions of multilayer composite dielectrics are discussed.

Zintl phase Mg₃X₂ (X=Sb, Bi) based thermoelectric materials have attracted much attention because of their non-toxic, low cost and high performance. Compared with polycrystalline materials, the Mg₃X₂ crystals are of great value in revealing material’s intrinsic and anisotropic thermoelectric properties, as well as providing effective strategies for enhancing electrical and thermal transport properties. Therefore, the recent progress of single crystal growth and thermoelectric properties for Mg₃X₂ crystals are systematically summarizes in this paper. Due to the volatility and causticity of Mg element, several different methods such as slow cooling method, directional solidification method, flux method, and flux Bridgman method are widely used for synthesizing Mg₃X₂ crystals, in which the flux Bridgman method is more competitive to prepare large size bulk crystals. Researchers found that both n-type and p-type Mg₃Sb₂ crystals show an anisotropy thermoelectric transport property. The crystal growth rate, the concentration of self-doped Mg element, the concentration of impurity doping or alloying elements have a great impact on both electrical and thermal transport properties for Mg₃Sb₂ crystals. So far, the p-type and n-type Mg₃Sb₂ crystals with ZT value of 0.68 and 0.82 are achieved, respectively. This paper reviews the recent progress of growth and thermoelectrics properties of Zintl phase Mg₃X₂-based crystals, revealing that the flux Bridgman method is the most effective method to produce large-sized Mg₃X₂-based crystals. Tuning chemical composition of Mg₃X₂-based crystal by doping and forming solid solution for optimal carrier concentration and band structure engineering is expected to further improve the thermoelectric performance of Mg₃X₂-based crystal. The above-mentioned growth method and research strategies provide a significant guidance for the in-depth understanding of the Mg₃X₂-based crystal in the future.

Densification of ceramic materials by conventional sintering process usually requires a high temperature over 1000 ℃, which not only consumes a lot of energy, but also forces some ceramic materials to face challenges in phase stability, grain boundary control, and co-firing with metal electrodes. In recent years, an extremely low temperature sintering technique named cold sintering process (CSP) was proposed, which can reduce the sintering temperature to below 400 ℃, and realize the rapid densification of ceramic materials through the dissolution- precipitation process of ceramic particles by using the transient solvent in liquid phase and uniaxial pressure. The advantages of CSP, including low sintering temperature and short sintering time, have attracted extensive attention from researchers, since it was firstly reported in 2016. At present, CSP has been applied to the sintering of nearly 100 kinds of ceramics and ceramic-matrix composites, involving dielectric materials, semiconductor materials, pressure-sensitive materials, and solid-state electrolyte materials. This paper firstly introduces the low-temperature sintering techniques’ development history, process and densification mechanism. Then, application of CSP in the field of ceramic materials and ceramic-polymer composites is summarized. Based on differences of solubility, application of CSP mainly on Li₂MoO₄ ceramics, ZnO ceramics, BaTiO₃ ceramics, and their composites preparations are introduced. Auxiliary effect of the transient solvent on cold sintering process is emphatically analyzed. Moreover, the high pressure issue in the cold sintering process and the possible solutions are discussed. At last, future development trend of cold sintering process is prospected.

The outbreak of corona virus disease 2019 (COVID-19) has aroused great attention around the world. SARS-CoV-2 possesses characteristics of faster transmission, immune escape, and occult transmission by many mutation, which caused still grim situation of prevention and control. Early detection and isolation of patients are still the most effective measures at present. So, there is an urgent need for new rapid and highly sensitive testing tools to quickly identify infected patients as soon as possible. This review briefly introduces general characteristics of SARS-CoV-2, and provides recentl overview and analysis based on different detection methods for nucleic acids, antibodies, antigens as detection target. Novel nano-biosensors for SARS-CoV-2 detection are analyzed based on optics, electricity, magnetism, and visualization. In view of the advantages of nanotechnology in improving detection sensitivity, specificity and accuracy, the research progress of new nano-biosensors is introduced in detail, including SERS-based biosensors, electrochemical biosensors, magnetic nano-biosensors and colorimetric biosensors. Functions and challenges of nano-materials in construction of new nano-biosensors are discussed, which provides ideas for the development of various coronavirus biosensing technologies for nanomaterial researchers.

The robust development of clinical medicine and biomaterials boosts diagnostic imaging, effective treatment, and precise theranostics in various diseases. The emerging interdiscipline of materials and medicine, termed as materdicine, aims to surmount the critical obstacles and challenges faced by traditional medicine, such as systemic toxicity, poor bioavailability, inferior site-targeting specificity, and unsatisfied diagnostic/therapeutic efficacy. Herein, the state-of-the-art advances regarding the applications of diverse medmaterials for disease diagnosis, therapy, and theranostics are systematically summarized in this review, especially focusing on the nanoscale medmaterials. We firstly emphasize and discuss biomedical imaging (e.g., optical imaging, magnetic resonance imaging, ultrasound imaging, computed tomography imaging) and therapeutic strategies (e.g., photothermal therapy, dynamic therapy, immunotherapy, synergistic therapy) in the field of cancer treatment. Furthermore, we highlight the important progress of medmaterials in the diagnosis and treatment of other kinds of diseases including orthopedic diseases, respiratory system, and brain diseases. Especially, the elaborated medmaterials for other representative biomedical applications, such as biosensing and antibacteria, are illustrated in detail. Finally, we discuss the current challenges and future opportunities for the practical application of these unique medmaterials in materdicine for accelerating their early realization of clinical translations, promoting the progresses of clinical medicine and benefiting the patients.

With the increase of packaging density of power electronic devices, the development of thermal interface materials with excellent thermal conductivity has received widely spread attention. Due to most traditional heat conductors showing relatively low thermal conductivity, synthesis of new high thermal conductive fillers is an important way to improve the thermal conductivity of thermal interface materials. In this study, boron phosphide (BP) particles were synthesized by a facile molten salt method, then mixed with boron nitride (h-BN) and filled into epoxy resin (EP) to prepare epoxy resin matrix composites (BP-BN/EP) by stirring and casting. With the three salts (NaCl : KCl : LiCl) method, the experimental data showed that the highest yield of BP reached 74%, 33% and 35% higher than that of the single salt method (41%) and the double salt method (39%), respectively. In the BP-BN/EP composites, BP and BN particles were uniformly dispersed in the EP matrix. When the hybrid filler loading at 30% (in volume), the thermal conductivity reached 1.81 W·m^-1·K^-1, 8.6 times of that of pure epoxy (0.21 W·m^-1·K^-1). The thermal conductivity improvement was related to the construction of thermal conductive network by BP particles linking adjacent BN sheets. In addition, to excellent thermal conductivity, the BP-BN/EP composites also showed good thermal stability and good thermodynamic properties. Therefore, the synthesized BP by molten salt method has great application prospects in the field of heat management.

Graphene has played a major role in wearable electronic textiles due to its excellent electrical conductivity, superior flexibility and environmental stability. In this work, a green-yellow reversible electrothermochromic fabric was constructed via a facial double side coating. The self-made graphene paste is coated on the surface of polyester fabric by screen printing technology. The hybrid thermochromic ink with reversible color-changing property is coated on the opposite side of the graphene layer by screen printing technology. Structural properties and discoloration principle of the fabric were analyzed. Their thermal and color-changing properties were studied by using infrared thermal imaging and colorimeter. The results show that the graphene forms a conductive layer with a thickness of 250 μm that allows Joule heating to supply the thermal resource for the electrothermochromic behavior. This fabric changes from green to yellow with a gradual heating that exceeded 45 ℃ at 12 V due to the ring closure and opening of crystal violet lactone. Its color change response time is about 15 s, while fading response time is about 27 s. The electro-thermochromic fabric is not disturbed once undergoing a bending angle range from 30° to 180° and the voltage-current curve remains stable. Performance of the fabric does not significantly degrade after 200 heating/cooling continuous cycles. In conclusion, a sensitive electro-thermochromic fabric with good cycle performance from green to yellow with the structure of graphene film‖polyester fabric‖thermochromic film is successfully prepared, which has a high application potential in the fields of military camouflage and wearable display.

BN nanofilms with hierarchical structure exhibite super-hydrophobicity, but they are not suitable for the large-scale production and application due to their complicated preparation process and expensive cost. Compared with common BN nanofilms, the application of super-hydrophobic coatings based on hydrophobic BN powders are more convenient. Herein, the hydrophobic single-phase BN powders were prepared by combustion synthesis method through magnesiothermic reduction reaction and acid washing, showing the water contact angle at (144.6±2.4)°. Their hydrophobic character lies in the micro-nano hierarchical structure of BN particles. The super-hydrophobic BN/fluorosilicone resin coatings were prepared using the combustion-synthesized hydrophobic BN powders as fillers. The water contact angle and sliding angle for 30% BN/fluorosilicone resin coatings (in mass) are (151.2±0.7)° and 8°, respectively, which are comparable to that of BN nanofilms fabricated by CVD method reported in the literature. This method is a convenient way to prepare super-hydrophobic organic-inorganic composite coatings by utilizing the hydrophobicity of ceramic powders. Therefore, hydrophobic BN powders and super-hydrophobic BN/fluorosilicone resin coatings are expected to have wide application.

Silicon carbide fiber reinforced silicon carbide (SiC_f/SiC) composites have become the preferred candidate for structural applications in advanced nuclear energy systems, because of their low neutron toxicity, neutron irradiation tolerance and high-temperature oxidation resistance. In recent years, both academia and industry either domestic or abroad have carried out a lot of researches on SiC_f/SiC composites for nuclear application, and numerous important achievements have been made. This paper summarized and analysed some critical directions of SiC_f/SiC composites for nuclear applications, including nuclear-grade SiC fibers, fibre/matrix interfaces, composite processing, modeling and simulation, corrosion behavior and surface protection, joining technology, as well as radiation damage. The key issues and potential solutions of SiC_f/SiC composites for nuclear applications have been pointed out in account to the requirements, anticipating to be beneficial to promoting further researches and final applications.

Oxygen reduction reaction (ORR) is the key reaction in cathode for fuel cells. Because of the sluggish kinetics, platinum (Pt) is widely used as the electrocatalysts for ORR. However, the high cost of Pt and poor stability of carbon black support under high voltage limit the commercialization and durability of fuel cells. Two-dimensional transition metal dichalcogenides (2D TMDs) possess large specific area, tunable electronic structure, and high chemical stability, making them a good candidate for ORR catalysts with high activity and durability. This paper reviews the recent progress of 2D TMDs-based ORR electrocatalysts. First, crystal structure, electronic properties, and ORR reaction mechanism are briefly introduced. Then some strategies for adjusting ORR performance of 2D TMDs are summarized, including heteroatom doping, phase conversion, defect engineering, and strain engineering. Meanwhile, the ORR activity enhancement arising from 2D TMDs-based heterostructures is also analyzed. Finally, perspectives are given for current issues and their possible solutions.

Spontaneous coagulation casting (SCC) is a novel in-situ ceramic forming method, not only universal for various ceramics but also working well at room temperature in air. Here presents the finding of SCC, involving an anion dispersant which acts as both dispersing and coagulating agent. Then, the difference between SCC and other in-situ coagulation methods in principle was elucidated. In SCC, particles participate in the formation of organic network which originates from hydrophobic interaction and hydrogen bonding among the dispersant molecular chains. The ceramic gel formed by SCC is a physical gel and possesses low density which is conducive to water transportation and stress relaxation during drying. In contrast, the one by conventional gelcasting is a chemical gel in which particles are fixed by a dense organic network. Based on the hydrophobic interaction, this review focuses on the design and synthesis of a series of SCC agents to meet the demand of forming dense and porous ceramics from particles with different sizes. That is, an anion dispersant is hydrophobically modified by a surfactant with a short or long chain. The obtained two agents are used for preparation of dense and porous ceramics, respectively. Progress of key technologies in this area including ceramic joining without interface, construction of grain orientation, drying, preparation of dense ceramics and porous ceramics, by SCC is summarized. Typically, alumina disc with a diameter up to 1010 nm and alumina parts with complicated shape such as dome and guide are shown. Future development of SCC is also proposed to enable SCC is a more universal forming technology for advanced ceramics with a large and/or complicated dimension.

Solar thermal radiant energy is abundant in storage and pollution-free, and is one of the most competitive clean energies in the future. In recent years, halide perovskite quantum dots (PQDs) are widely used in solar cells and luminescent concentrator solar cells due to their excellent photoelectric properties and unique advantages such as quantum confinement effect and solution processing, and possess vast application prospects, but they are still facing many challenges in future commercial applications. In this review, optimization strategies for improving cell performance are emphatically summarized combined with the domestic and foreign research progress in the field of PQD solar cells. The application of PQDs in luminescent concentrator cells is introduced. Finally, the current challenges in this field are elaborated, and its development trends are prospected. This review provides some ideas for the design and development of the photovoltaic technology in the future.

Ceramics, with its excellent thermal, physical and chemical properties, have great potential applications in various fields, such as aerospace, energy, environmental protection and bio-medicine. With the development of relevant technology in these fields, the structural design of core components is increasingly complex, and the internal microstructures gradually become customized and gradient. However, the hard and brittle features of ceramics make it difficult to realize the forming of special-shaped parts by traditional manufacturing methods, which in turn limits further application. As a rapidly developing additive manufacturing technology, laser additive manufacturing technology presents a momentous advantage in the manufacturing process of extremely precision ceramic components: free molding without mold and support, quick response feature and short developing cycle, etc. At the same time, the technology can realize the flexible deployment of ceramic parts, which is expected to solve the problems mentioned above. Three kinds of powder-based laser additive manufacturing techniques of ceramic were reviewed in this paper: selective laser sintering and selective laser melting based on powder bed fusion technology; laser engineered net shaping based on direct energy deposition technology. The forming principle and characteristics were mainly discussed; the research progress of ceramic green body densification process in selective laser sintering technology and the forming principle, propagation mechanism and control methods of ceramic green body cracks in selective laser melting, and laser engineered net shaping technology were reviewed; the technical characteristics of selective laser sintering, selective laser melting and laser engineered net shaping technologies in shaping of ceramic parts were compared and analyzed; and the future development trends of laser additive manufacturing technology of ceramic parts were prospected.

Piezoelectric ceramic is a type of functional ceramic, which is able to convert the mechanical signal and the electronic signal mutually. Composed of piezoelectric ceramics and organic phase, piezoelectric composites have different kinds of connectivities, which not only determine the diverse applications of piezoelectric devices, but also promote the development of various shaping techniques in manufacturing piezoelectric materials and devices. In comparison with the traditional shaping methods, the most distinguishable advantage of additive manufacturing lies in its ability of quickly shaping a small batch of samples into geometrically complex designs without a mould, which makes it a highly suitable technique for investigating piezoelectric ceramics and its derivative devices in different kinds of connectivities. Meanwhile, the final additively manufactured samples require only tiny post-processing, have a high rate of utilization of the raw material and do not need cutting fluid during manufacturing. Due to the above-mentioned advantages, it attracts the widespread concerns from both academic and industrial communities. When focusing in the field of additive manufacturing ceramics, the data of scientific reports in additive manufacturing functional ceramics and devices prove that it is still in a growing period. In the perspective of different additive manufacturing techniques, this article discusses and compares additive manufacturing of both lead-free and lead-based piezoelectric ceramics in the aspects of their historical development of each technique, preparation of the raw materials, geometrical designs, measurement of functional properties, and applications of the printed samples, and forecasts the future development based on the current benefits and drawbacks of each additive manufacturing technique.

Na-ion batteries, which currently use flammable and explosive organic electrolytes, now urgently need to develop high performance sodium ion solid electrolyte to realize more safe and practical application. Na₃Zr₂Si₂PO₁₂ is one of the most promising solid sodium electrolytes for its wide electrochemical window, high mechanical strength, superior air stability and high ionic conductivity. But its inhomogeneous mixing of the ceramic particles with the binders causing much more pores in the green bodies makes it difficult to obtain high-density and high-conductivity ceramic electrolytes after sintering. Herein, the spray drying method was used to enable Na₃Zr₂Si₂PO₁₂ particles uniformly coated with binders and granulated into spherical secondary ones. The as-prepared normal distributed particles can effectively contact each other and reduce porosity of ceramic green body. After sintering, Na₃Zr₂Si₂PO₁₂ ceramic pellets via the spray drying show relative density of 97.5% and ionic conductivity of 6.96×10^-4 S∙cm^-1 at room temperature. In contrast, the relative density and room-temperature ionic-conductivity of Na₃Zr₂Si₂PO₁₂ ceramic pellets prepared without the spray-drying are only 88.1% and 4.94×10^-4 S∙cm^-1, respectively.

BaTiO₃ has a wide range of applications in microelectromechanical systems and integrated circuits due to its excellent dielectric, ferroelectric, piezoelectric, and pyroelectric properties. For the applied research and device applications of BaTiO₃ films, reducing its deposition temperature to be compatible with the CMOS-Si technology is an important Challenge. Here, with the help of a LaNiO₃ buffer layer which has a closely-matched lattice with BaTiO₃, (001)-textured BaTiO₃ films were sputter-deposited at 450 ℃ on single crystalline Si(100) substrates, which consisting of well-cryotallized, evenly-distributed columnar nanograins with an average grain size of 27 nm. Our result showed that this deposition temperature can maintain the columnar nanograin structure with a relatively large grain size, leading to a good ferroelectric performance. In addition, a small residual strain on Si was also helpful to improve its ferroelectric and dielectric properties. The remnant polarization and saturated polarization of these BaTiO₃ films reached 7 and 43 μC·cm^-2, respectively, while leakage current densities were as low as 10^-5 A·cm^-2 at an applied electric field of 0.8 MV·cm^-1. These BaTiO₃ films also displayed excellent frequency stability with a low dielectric loss in which relative dielectric constant measured to be ~155 at 1 kHz, slightly being reduced to ~145 after increasing the frequency to 1 MHz. Meanwhile, the dielectric loss slightly increased from 0.01 at 1 kHz to 0.03 at 1 MHz. Lastly, through capacitance-voltage (C-V) tests, these films exhibited a large dielectric tunability of~51% and a figure of merit (FOM) of ~17 (@1 MHz). These films have a good potential for applications in tunable dielectrics.

As an important branch of nonlinear optics, second harmonic generation (SHG) is becoming one of the most important means to characterize crystal structure. Among various methods of characterization, because of nondestructive detection, high stability, tunability, ultrafast response, polarization sensitivity, versatility and simplicity, SHG is widely used to characterize the structure of two-dimensional (2D) materials. It provides important information for the physical properties and functional applications of 2D materials, as well as greatly promotes the rapid development of basic research on 2D materials. Here, the current state of the art focuses on the recent research work of SHG in 2D material structure characterization. Firstly, the principle of the second harmonic generation is briefly introduced. Then, the second harmonic generation device with femtosecond laser connected to confocal Raman spectrometer is taken as an example to present the mechanism of SHG. Afterwards, the applications of SHG are demonstrated in the thickness of interlayer stacking of 2D materials, the stacking angle between different layers of 2D materials, the grain boundary and the crystal orientation of monolayer 2D materials. The second harmonic intensity is used as a direct and sensitive means to monitor the strain amplitude, and the SHG signal changes are used to track defects in materials. Meanwhile, the importance of multi-dimensional correlation analysis of second harmonic generation, Raman spectroscopy and photoluminescence in comprehensive and in-depth characterization of materials is also explored. Finally, the potential research directions and prospects based on SHG in material characterization in the future is prospected.

Optical property, such as color, transmittance, reflectance and emissivity, of electrochromic materials can be changed reversibly under low applied voltages. Electrochromic materials have a wide range of regulatable spectrum, which can realize the broadband control from the visible to mid-far-infrared. Electrochromic materials show a wide application prospect in the fields of intelligent window, display, anti-glare rearview mirror, intelligent thermal control, and camouflage. At present, most of researches on inorganic electrochromic materials focus mainly on transmission characteristics, but less on reflection characteristics. This is mainly because most inorganic electrochromic materials have single color and are not as easy to design as organic electrochromic materials. In recent years, through special preparation and structural design, the research on reflective properties of inorganic electrochromic materials has gradually attracted researchers’ attention. Based on reflection characteristics of inorganic electrochromic materials, methods and principles of regulating the reflectance spectrum in the visible near infrared to mid-far-infrared bands are introduced, and the latest research progress is summarized. Within the visible band, reflectance spectrum control is mainly achieved by vanadium pentoxide (V₂O₅) and V₂O₅ doping, microstructure of one dimensional photonic crystal, Fabry Perot nanocavity structure and localized surface plasmon resonance (LSPR). Within the mid-to-far infrared band, electrochromic devices (ECDs) based on the molecular vibration absorption of tungsten oxide (WO₃) or other electrochromic materials and related theory are designed and fabricated to regulate reflectance spectra. Finally, the practical application of inorganic electrochromic materials in future is prospected.

Vanadium dioxide (VO₂), as a transition metal oxide, has thermochromic property, which undergoes metal to insulator transition (MIT) in response to external temperature changes, and is accompanied by numerous changes in physical property. It has attracted widespread attention in the field of smart windows. In recent years, research on the preparation method of VO₂, the phase change mechanism, and the improvement of optical performance are quite rich. However, practical applications still face technical bottlenecks and challenges such as higher intrinsic transition temperature (T_c), lower luminous transmittance (T_lum), insufficient solar modulation ability (ΔT_sol), nonideal metastability and durability, and uncomfortable color for human eyes (brownish yellow). At present, there are many researches related to the improvement of the performance of VO₂ itself owing to its insufficient optical property, and general methods for improving its performance such as elements doping, multilayer film structure design, and microstructure design have been widely adopted. This review summarizes the general performance improvement strategies of VO₂ film, and highlights the latest research progress of VO₂-based smart window service performance, low-temperature flexible preparation and color modulation in practical applications. Future development trends are also discussed in terms of skin comfort and environmental friendliness.

Synchrotron Radiation (SR) is the electromagnetic radiation emitted along the tangent direction of the electron orbit by high-speed electrons moving in a circular accelerator when passing through a bending magnet. SR source, as a platform-type scientific and technological infrastructure, plays an important supporting role in the research and development of inorganic materials. SR techniques become an indispensable research tools of modern science and technology, and inorganic materials are one of the main application fields of SR techniques. Compared with conventional light source used for research, SR techniques in the study of inorganic materials have following obvious advantages: 1) higher obtained data qualities; 2) better spatial and temporal resolutions; 3) easier simulated in-situ and material service environment; 4) synchronously acquiring multi-scale, multi-faceted and multi-type structural information; 5) new means more likely to detect new structural characteristics. SR techniques help solve some key scientific problems in the field of inorganic materials, and greatly promote their research. Firstly, this paper briefly introduces the current status of SR sources and their three existing domestic SR facilities: Beijing Synchrotron Radiation Facility (BSRF), Shanghai Synchrotron Radiation Facility (SSRF), and National Synchrotron Radiation Laboratory (NSRL). Secondly, some application examples related to inorganic materials research are given from the four aspects of X-ray diffraction, scattering, spectroscopy and imaging. Finally, summary and prospect are given to the SR source, the structurally characterization techniques, and their application in inorganic materials.

The triboelectric nanogenerator (TENG) is a kind of green power source which can harvest and transform small mechanical energy into electricity. Triboelectric nanogenerators have various active materials, simple structures, and easy to integrate with other devices. However, its relatively low output power density hinders the further practical application of TENGs. How to improve the output performance of TENGs through the modification of the active triboelectric materials is one of the hottest spots. It is a facile and effective way to introduce functional fillers into polymer substrates to fabricate composite materials, which improve the triboelectricity of pristine material and bring new functions for the device. Thus, composite films are widely used in TENGs. For example, inorganic fillers like TiO₂, SiO₂, BaTiO₃, ZnSnO₃, MoS₂, r-GO sheets, and nanofibril-phosphorene have been introduced into polymers to improve the output power density of TENGs by dozens of times. Based on domestic and international research, this review introduces the applications of the composite film in TENGs. The improvements of TENGs induced by the fillers are discussed from two aspects: the surface property and electrical property. Finally, future challenges in developing composites based TENGs are prospected.

Rare earth ions doped Gd₂O₂S scintillators are new type of oxysulfide scintillators, which have been developed since 1980s. The Gd₂O₂S matrix with cross section of high density and high thermal neutron absorption has high X ray and thermal neutron stopping capacity. The doping of different rare earth ions (Pr³⁺, Tb³⁺, etc.) shows fast decay or high light yield, which plays a very important role in application of scintillation. Composition control of oxysulfide is always a key problem to be solved in the synthesis process. However, the high melting point of Gd₂O₂S material and the serious volatilization of sulfur restrict the preparation of Gd₂O₂S single crystals, with high optical quality and excellent scintillation performance. Ceramic is the main application form of Gd₂O₂S scintillation material. Its pure phase Gd ₂O₂S phosphors with small particle size, narrow particle size distribution and low agglomeration is the key to sintering high quality scintillation ceramics. These ceramics prepared by simply increasing the sintering temperature produce a large number of sulfur vacancies and oxygen vacancies, decreasing the scintillation properties. Therefore, preparation of Gd₂O₂S scintillation ceramics usually need pressure assistance to increase the production cost. In this paper, their scintillation mechanism and research situation are introduced firstly. Then, their fabrication process, solution of defects removal, research status and applications in neutron imaging and medical X-CT fields are overviewed. Finally, we summarized the previous and prospected the future development of Gd₂O₂S scintillation ceramics.

Due to high power, high brightness, small size, energy saving, and environment friendliness, solid-state lighting has been becoming the most promising lighting technology in this century. As the key material of solid-state lighting, the luminescent properties of phosphors directly determine the crucial parameters such as the color rendering index, luminous efficacy and reliability of solid-state lighting devices. Compared with single crystals, phosphor glasses, phosphor films and quantum-well LEDs, phosphor ceramics have become the most excellent phosphor materials for high-power solid-state lighting due to its excellent thermal and optical properties and easy control of microstructure. In the future, phosphor ceramics is expected to be more widely used and developed in automotive headlights, outdoor lighting, laser TVs, laser cinema projectors, and other fields, and have a broad market prospect. In this review, design principles of high-power solid-state lighting phosphor ceramics are put forward firstly, and then their research progress of oxide phosphor ceramics (mainly refers to Y₃Al₅O₁₂) and nitrogen/oxynitride phosphor ceramics are reviewed mainly. Finally, the development of phosphor ceramics for high-power solid-state lighting is prospected.