One-dimentional high-entropy metal carbides have attracted significant attention for their exceptional physical and chemical properties, which endow them with great potential for applications in structural and functional fields. However, there is a lack of stable preparation methods, particularly on flexible substrates. In this study, we successfully synthesized high-entropy (Ti_0.2Zr_0.2H_f0.2Nb_0.2Ta_0.2)C (HEC) nanowires through a precursor pyrolysis method using waste cotton fabric as both a flexible substrate and a carbon source. Interestingly, the growth of the nanowires followed a catalyst-assisted vapor–liquid–solid mechanism, driven by the dissolution of metals and carbon-containing molecules originating from the polymer precursors and thermal decomposition of cotton fabric in the Fe-Ni alloy. This process involved nucleation of HEC and subsequent nanowire growth. The as-prepared HEC nanowires with diameters ranging from 0.05 to 0.1 μm were randomly distributed on carbonized cotton fiber substrate without a specific orientation, forming an interconnected multiscale conductive network. Owing to the synergistic effects including electrical conduction loss, dipolar polarization loss arising from lattice distortion in HEC, and polarization loss generated by numerous heterojunctions within the material, the prepared HEC nanowires exhibit outstanding electromagnetic interference (EMI) shielding performance in the X-band (8.2–12.4 GHz). For instance, the material achieved an EMI shielding effectiveness (SE) of 57.55 dB at a thickness of 1.35 mm. This study introduces novel perspectives and scalable approaches for the preparation, formation mechanism, and functional applications of nanostructured high-entropy ceramics.

Design and optimization of electrode material structures are critical steps in the development of supercapacitors. This work presented a design strategy based on SiC nanowires (NWs) as supercapacitor electrode with gradient pore structure, superhydrophilicity, and enhanced conductivity. SiCNWs were in-situ fabricated on a carbon fabric substrate radially via chemical vapor deposition (CVD), constructing conical channels with gradient pore sizes that generate capillary forces and promote ion transport. An ultrathin pyrolytic carbon (PyC) shell (4.98 nm) was coated on the SiCNWs, to improve electrical conductivity without compromising pore structure or wettability. SiCNWs@PyC electrodes with a diameter of ~0.93 μm exhibited excellent electrochemical performance from 0 to 60 ℃. At 25 ℃ and a current density of 0.2 mA/cm², the areal capacitance of SiCNWs@PyC electrode was 32.48 mF/cm², representing 227.58% of the areal specific capacitance of pure SiCNWs. At 60 ℃, the capacitance remained high at 28.09 mF/cm² under the same current density. The in-situ growth strategy and high mechanical stability of the material enabled the symmetric supercapacitor to maintain outstanding rate performance and cycling stability across a wide temperature range. The SiCNWs@PyC core-shell nanostructure is a promising supercapacitor electrode material, offering valuable insights for the development of next-generation energy storage devices.

C/C composites are key thermal structural materials for hot-end components of aerospace vehicles. However, their susceptibility to oxidation and ablation at high temperatures limits their applications in extreme environments. Therefore, it is particularly important to improve the ablation resistance of C/C composites. The research progress of anti-ablation C/C composites at home and abroad in recent years are systematically reviewed, focusing on 3 aspects: matrix modification, coating protection, and matrix-coating integration. In terms of matrix modification, based on the differences in component characteristics, it is divided into single-phase ceramics, multiphase ceramics, multi-component and high-entropy ceramics modified C/C composites, revealing oxygen blocking and anti-ablation mechanisms of oxidation products of ceramics. The coating technology focuses on analyzing the design principles and ablation behaviors of single-layer coatings, multi-layer composite coatings with gradient structure, micro/nano structure toughened coatings, and coatings with embedded structure interface, clarifying the mechanisms of interface matching optimization in alleviating thermal mismatch of coatings and ablation behaviors. Finally, according to the application requirements for extreme ablation environments, the future development directions for C/C composites are proposed, including oxidation and ablation mechanism analysis, optimization of structure and composition of composite materials, functional design of components, and cost-effective fabrication processes.

The mechanics of structural ceramics, especially the toughness, are crucial to their service reliability and need to be continuously optimized. Inspired by the “brick-mortar” structure and further adjusting the microstructure of “mortar” on the interface, ceramic with strength and toughness up to 444.16 MPa and 13.79 MPa⋅m^1/2 is constructed by hot pressed sintering with alumina (Al₂O₃) as brick and vertical graphene (VG) with active atomic edges as mortar. Relying on the covalent interface between VG grown in-situ and Al₂O₃, the sliding of Al₂O₃ links the shear-deformation process of the crosslinked and interlocked nanointerface formed by VG, making the VG-enhanced Al₂O₃ ceramics (AVG) obtain super toughness. Moreover, the structure of interlocked VG-nanointerface exhibits an excellent high-temperature resistance, which makes AVG still show the excellent strength of 437.66 MPa and toughness of 11.16 MPa⋅m^1/2 after heat treatment at 1500 °C for 100 h and they are respective 2.51 times and 3.18 times higher than Al₂O₃ in the same condition. This work provides a new thought for the preparation of high-strength, ultra-tough and high-temperature mechanical stable ceramics.

Carbon fiber reinforced carbon-based composites are considered to be an ideal lightweight material with exceptional high-temperature mechanical performance. Nevertheless, their high conductivity result in a strong reflection rather than absorption of electromagnetic wave (EMW) for the stealth application. To address this challenge, a novel carbon-based composite made of multi-scale lossy phases (Carbon nanotubes (CNTs), SiC nanowires (SiC_nws), and Carbon fiber (C_f)) and impedance matching phase (SiOC ceramic) was fabricated by the precursor-derived method. The prepared SiC_nws/CNTs/C_f-C/SiOC (SCC-CS) composites exhibit an effective absorption (EAB) of 2.4 GHz at a thickness of 1.9 mm and a minimum reflection loss (RL_min) of −58.44 dB (99% absorption) in the X band. The EMW absorption of the composite is attributed to the multiple loss mechanisms and favorable impedance matching with free space, caused by the multi-conductive phase and SiOC in the composite. In addition, the fabricated composites also have thermal insulation properties and can effectively achieve radar cross-sectional (RCS) reduction, which are promising aerospace composites with the integration of structure and function.

HfC–SiC-modified carbon/carbon composite (C/C–HfC–SiC) sharp leading edges (SLEs) were prepared via precursor infiltration and pyrolysis for potential hypersonic applications. The effect of SiC proportion on the ablation behavior of the SLEs under oxyacetylene flames with 2.38 MW/m² and 4.18 MW/m² was investigated. The preferred sample with a volume ratio of HfC to SiC of 0.74 possessed almost zero degradation (linear recession rate 0.6 μm/s) up to a temperature of 2371 ℃. As the temperature increases to 2527 ℃ in the latter condition, the SLE with less SiC (the volume ratio of HfC to SiC is 1.10) exhibited a linear recession rate of 1.03 μm/s during cyclic ablation of 3 × 40 s. Relatively more SiC addition is favorable under lower heat flux due to the better oxygen barrier performance of the scale. However, superior ablation resistance is available under higher heat flux with less SiC addition due to the higher thermal stability of the resulting oxide scale.

For the inadequate interlaminar strength of 2D carbon/carbon (C/C) composite, in-situ grown carbon nanotubes (CNTs) reinforcing strategy was put forward to strengthen the interlaminar matrix at the nanoscale and inhibit the interlaminar cracking. CNT morphology is an essential factor in influencing the enhancement effect. Herein, the influence of in-situ grown CNT morphology on the microstructure and mechanical properties of C/C composite was deeply studied. The radially-aligned straight CNTs could induce the formation of highly-ordered pyrolytic carbon (PyC), while PyC in randomly-distributed curved CNTs concentrated area exhibits an isotropic structure. Further, radially-aligned straight CNTs show better improvement on the flexural and shear strength of C/C composites. According to the fine structural characterization and finite element simulation, the influence mechanism of CNT morphology was revealed. CNT morphology can influence the stress distribution in the PyC protective layer, and compared with radially-aligned straight CNTs, randomly-distributed curved CNTs induce higher tensile stress in the PyC protective layer, which has a detrimental impact on the flexural and shear properties of C/C composite. This work provides novel insights into the effect of CNT morphology on the microstructure and mechanical properties of C/C composites, which gives a basis for the structural design and preparation of CNTs reinforced C/C composites.

To repair the damaged SiC coated C/C composites, a double-layer system including a Sm-doped borosilicate glass external layer and a SiSiC inner layer was prepared by a slurry-based laser cladding technique. Isothermal oxidation experiment and indirect/direct thermal-radiation measurements were performed. The results showed that the absorbance of borosilicate glass to the laser at 900–1200 nm was improved significantly by Sm-doping. Consequently, the repaired coating with a more compact structure and better oxidation resistance was obtained. After oxidation at 1773 K for 10 h, the mass loss of the damaged sample could be reduced by 74.98% with repairing. By increasing laser-absorption and reducing viscosity, the thermal-radiation property of the repaired coating was enhanced to decrease the surface temperature greatly. A repair system with excellent thermal protection performance was achieved.