Silicon carbide (SiC) aerogels represent an emerging class of multifunctional materials that integrate a three-dimensional (3D) porous architecture with the intrinsically superior physicochemical properties, exhibiting considerable promise for thermal insulation and electromagnetic wave (EMW) absorption under extreme environments. This review systematically summarizes recent advances in the fabrication strategies, structure-property relationships, and functional performance of SiC aerogels. For thermal insulation, the highly porous framework effectively suppresses solid-state heat conduction and gas convection, while the wide bandgap semiconducting nature of SiC enables efficient thermal radiation attenuation, collectively ensuring excellent insulation stability at elevated temperatures. SiC aerogels deliver broadband and strong absorption through a combination of moderate electrical conductivity, abundant interfacial polarization, optimized impedance matching, and multiple scattering within the 3D porous network with respect to EMW absorption. Moreover, recent studies demonstrate that synergistic enhancement of thermal insulation and EMW absorption can be achieved via multicomponent compositional engineering, hierarchical structural design, and advanced fabrication techniques, thereby accelerating the deployment of SiC aerogels in frontier applications including aerospace, defense systems, and thermal management for emerging energy technologies.

Achieving compatible electromagnetic (EM) defense across both microwave and Terahertz (THz) regimes remains a formidable challenge in the development of advanced stealth materials. Herein, a novel MXene/liquid metal (LM)/Ni chain composite is strategically engineered through an interfacial synergy modulation and 1D magnetic structure induction strategy, enabling high-efficiency co-attenuation across the microwave-THz spectrum. This architecture synergistically combines the conductive network of MXene, LM-induced interfacial polarization, and the magnetic loss from Ni chains to achieve superior impedance matching. Remarkably, with a mere 5 wt% filler loading, the composite achieves a record-low reflection loss (RL_min) of -63.1 dB and an effective absorption bandwidth (EAB) of 6.72 GHz. Simulation results further validate its immense potential for radar stealth applications in both civil and military coatings. When fabricated into flexible films, the material demonstrates exceptional EM attenuation in the 0.1-1.6 THz band, yielding a shielding effectiveness (SE) and absorption efficiency of 69.6 dB and 68.1dB, respectively. Mechanism analysis reveals that the multiscale conductive network, pronounced interfacial polarization, and magneto-dielectric synergistic loss collaboratively facilitate high-efficiency energy dissipation across multiple frequency bands. This work provides a novel design strategy for the development of lightweight, ultra-thin, and ultra-broadband microwave-THz absorption/shielding materials.

Ceramic-based electromagnetic interference (EMI) shielding materials have emerged as promising solutions because of their tunable dielectric and magnetic properties, excellent chemical stability, and favorable cost‒performance ratio. Despite their advantages, enhancing electrical conductivity and optimizing microstructural design remain key technical challenges. This review presents a systematic analysis of the working mechanisms, advanced fabrication techniques, and performance optimization strategies for ceramic-based EMI shielding materials. This study provides an in-depth analysis of the key factors influencing shielding efficiency and discusses the shielding mechanisms and performance enhancement strategies for both conventional ceramics (e.g., silicon carbide and ferrites) and advanced ceramics (e.g., MXenes and high-entropy ceramics). Future research directions are identified, including wideband shielding design to meet the requirements of 5G and terahertz communication; the integration of mechanical, thermal, and electromagnetic functionalities; and the development of intelligent, responsive materials. Additionally, this review highlights the potential of machine learning (ML) and artificial intelligence (AI) in accelerating material design and performance optimization. By critically analyzing the interrelationships among material properties, fabrication processes, and shielding mechanisms, this work offers a comprehensive perspective on the innovative application of advanced ceramics in EMI shielding, with the aim of bridging the gap between fundamental research and industrial implementation.

Despite the extensive research conducted on dielectric–magnetic coupling in metal-organic frameworks (MOF)-derived absorbers, the underlying mechanisms associated with defects, interfaces, and orbital hybridization remain inadequately investigated. To address this, we developed coral-like MOF-derived nickel–phosphorous@carbon (NP@C) nanocomposites by adjusting the pyrolysis temperature, revealing for the first time the link between structure and electromagnetic (EM) performance. The composite features nickel phosphide nanoparticles (Ni₁₂P₅ core/Ni₂P shell) embedded in an amorphous carbon matrix, where a unique crystal orientation and interfacial coupling enhance EM wave dissipation. The calculations show that charge transfer (0.66e) at the C–Ni₁₂P₅ interface increases conductance loss, whereas the C–Ni₂P–Ni₁₂P₅ heterostructure generates interfacial polarization and defect states via negative charge transfer (0.20e), synergistically enhancing dielectric and magnetic loss. Electronic structure analysis revealed that sharp Ni 3d orbital peaks near the Fermi level coexist with broad carbon matrix peaks, enabling both conductive and spin-related magnetic loss mechanisms. The NP@C nanocomposite achieves a reflection loss of −54.1 dB and an effective absorption band covering 4.1 GHz at a thin thickness of 1.37 mm. This study clarifies the atomic- and electronic-level EM response mechanisms of MOF-derived carbon materials, offering new insights for designing high-performance absorbers.

Transition metal carbides exhibit outstanding mechanical properties but suffer from a critical hardness‒toughness trade-off. Spinodal decomposition-mediated phase separation, induced by high-temperature aging, is an effective strategy for enhancing the mechanical properties of carbide ceramics. However, the typically high stacking fault energy in carbide ceramics restricts the dislocation pinning effects of spinodal decomposition interfaces, hampering potential hardness and toughness improvements. Guided by first-principles calculations, this study employs (Ti,Zr)C carbide ceramics as a representative system and systematically lowers its stacking fault energy through nitrogen (N) incorporation. With optimized composition and controlled aging, distinct stacking faults emerged after short-term aging. As the aging time increased, these stacking faults progressively transformed into dislocation sources, facilitating dislocation multiplication. Mechanical testing revealed that samples incorporating 25% N followed by aging exhibited significant enhancements: The hardness and fracture toughness increased by approximately 40% and 50%, respectively, compared with those of the initial material. However, at higher N concentrations, excessive elastic strain energy accumulation induced lamellar thickening, diminishing the extent of improvement in hardness and toughness. This work designs a strategy to lower the stacking fault energy in carbide ceramics, overcoming its constraint on performance enhancement via spinodal decomposition and enabling hardness‒toughness synergy via spinodal decomposition through theoretical and processing solutions.

One-dimensional tantalum carbide (TaC) nanorods are considered promising candidates for high-temperature electromagnetic wave (EMW) absorption because of their intrinsically high electrical conductivity and exceptional thermal stability. However, conventional synthesis approaches typically yield products with low quality and poor efficiency, limiting their practical applicability. Here, we report the rapid and scalable synthesis of high-quality TaC nanorods via a molten salt-assisted carbothermal reduction strategy integrated with microwave heating. The formation of well-defined one-dimensional TaC nanorods was achieved within 20 min at 1300 °C by precisely tuning the precursor composition (Ta₂O₅ : C : NaCl : Ni = 1 : 8 : 2 : 0.08). The resulting TaC nanorods exhibit notable EMW absorption properties, with a maximum effective absorption bandwidth (EAB_max) of 3.0 GHz at a simulated thickness of 1.0 mm and a minimum reflection loss (RL_min) of −30.5 dB. Off-axis electron holography reveals pronounced charge accumulation at the Ta₂O₅ shell/TaC core interface, indicative of interfacial polarization effects. Furthermore, radar scattering cross-section (RCS) simulations demonstrate substantial attenuation of the backscattered signal from a perfect electric conductor (PEC) substrate coated with the TaC layer, with the strongest electromagnetic energy dissipation observed at a coating thickness of 1.0 mm. These results underscore the viability of microwave-assisted synthesis as an efficient and sustainable route for producing high-performance TaC nanorods for EMW absorption applications under extreme thermal conditions.

Titanium dioxide (TiO₂) exhibits weak surface electron polarization and a poor response in the microwave region, resulting in its limited electromagnetic (EM) loss capability, which restricts its application in EM wave absorption. Recent research has revealed that the reduced phase of TiO₂, denoted as Ti_xO_2x-1 (1≤x≤10), possesses both metallic and semiconducting properties. This duality, coupled with its relatively high electrical conductivity, positions Ti_xO_2x-1 as a promising candidate for the next generation of EM wave absorbers. However, current investigations into Ti_xO_2x-1 absorbers primarily focus on the EM property modulation of black TiO₂ and its composites, while the influence of crystal structure, lattice defects, and band structure on the EM parameters and absorption performance of Ti_xO_2x-1 absorbers remains unclear. Consequently, there is a lack of a comprehensive Ti_xO_2x-1 absorber system both domestically and internationally. Based on the fundamental principles of EM wave absorption materials, this study discusses the crystal structure and formation mechanism of Ti_xO_2x-1 and defective TiO₂, as required by semiconductor metal oxides. The paper summarizes the high-efficiency EM wave absorption properties of TiO₂-derived Ti_xO_2x-1 absorbers with various texture designs, achieved through defect engineering and interface engineering. Focusing on the challenges of "poor absorbing performance" and "unclear absorbing mechanisms" in Ti_xO_2x-1 absorbers, this work aims to achieve optimal design of Ti_xO_2x-1 materials, enhance their absorbing capabilities, and establish an electromagnetic control mechanism for oxide-semiconductor absorbers. By employing methods such as defect regulation, compositional optimization, and interface design, multiple EM loss mechanisms including conductivity loss, dipole polarization, interface polarization, and coupling effects, are established and optimized. Accordingly, this approach improves the impedance matching and EM loss capabilities of Ti_xO_2x-1-based absorbers, ultimately resulting in absorbers with superior wave-absorbing performance. Finally, by integrating domestic and international research progress, this paper proposes a novel design strategy for Ti_xO_2x-1 absorbers, which holds significant implications for the future development and application of semiconductor metal oxide absorbers.

Multi-component occupancies of perovskite materials (ABO₃) have brought diverse crystallographic distortions and highly tunable defect structures. These structural features enable ABO₃ to have customizable dielectric and magnetic properties, offering new opportunities for advancing microwave absorbing materials. In this study, entropy-driven strategies, including composition optimization, structural/defective design, microstructure engineering, and microwave absorption simulation, are proposed to improve the microwave absorption capacity of (Ba_1/3Sr_1/3Ca_1/3)FeO₃. The hexagonal perovskite structure (Ba_1/3Sr_1/3Ca_1/3)FeO₃ prepared at 1100 °C exhibits exceptional electromagnetic wave absorption properties, with a minimum reflection loss of −40.58 dB at a thickness of 1.2 mm and a maximum effective absorption bandwidth of 4.16 GHz. The results indicate that the interconnection of octahedra, and structural distortions, oxygen vacancies, and other defects enhance the dielectric polarization of the material, leading to excellent wave absorption performance. The entropy-driven design strategy for perovskite ABO₃ materials offers valuable insights for the development of advanced electromagnetic wave absorption materials.

Ca²⁺/Cr³⁺ co-doped LaAlO₃ infrared (IR) ceramics have been proven to be potential energy-saving materials for high-temperature industries because of their high emissivity and high-temperature stability. However, Cr⁶⁺ formation commonly occurs in materials and poses environmental and health risks, such as Cr⁶⁺ dissolution in water and CrO₃(g) volatilization. In this study, we combined high emissivity with in situ detoxification by introducing residual Al₂O₃ into Ca²⁺/Cr³⁺ co-doped LaAlO₃ ceramics. Compared with the undoped ceramics, the addition of 20 wt% residual Al₂O₃ resulted in a 78.5% reduction to 18.44 mg/kg (lower than the EU standard of 20 mg/kg) in Cr⁶⁺ dissolution and a decrease in 77.8% CrO₃(g) volatilization. This significant detoxification effect can be attributed to the formation of CaAl_12−xCr_xO₁₉. Additionally, as the residual Al₂O₃ content increased from 5 to 20 wt%, the ceramics maintained high emissivity, above 0.896 in the near-infrared band and 0.781 in the mid-infrared band. Furthermore, the IR coating effectively increased the surface temperature (from 767.1 to 790.7 °C/min) and the heat radiation of the heating source, increasing the heating rate from 31.7 to 34.6 °C/min during water heating. This work offers a promising approach for designing environmentally friendly IR ceramics with excellent IR performance for energy-saving applications in the high-temperature industry.