Silicon carbide (SiC) has been widely concerned for its excellent overall mechanical and physical properties, such as low density, good thermal-shock behavior, high temperature oxidation resistance, and radiation resistance; as a result, the SiC-based materials have been or are being widely used in most advanced fields involving aerospace, aviation, military, and nuclear power. Joining of SiC-based materials (monolithic SiC and SiC_f/SiC composites) can resolve the problems on poor processing performance and difficulty of fabrication of large-sized and complex-shaped components to a certain extent, which are originated from their high inherent brittleness and low impact toughness. Starting from the introduction to SiC-based materials, joining of ceramics, and joint strength characterization, the joining of SiC-based materials is reviewed by classifying the as-received interlayer materials, involving no interlayer, metallic, glass-ceramic, and organic interlayers. In particular, joining processes (involving joining techniques and parameter conditions), joint strength, interfacial microstructures, and/or reaction products are highlighted for understanding interfacial behavior and for supporting development of application-oriented joining techniques.

One-dimensional nanofibers can be transformed into hollow structures with larger specific surface area, which contributes to the enhancement of gas adsorption. We firstly fabricated Cu-doped In₂O₃ (Cu-In₂O₃) hollow nanofibers by electrospinning and calcination for detecting H₂S. The experimental results show that the Cu doping concentration besides the operating temperature, gas concentration, and relative humidity can greatly affect the H₂S sensing performance of the In₂O₃-based sensors. In particular, the responses of 6%Cu-In₂O₃ hollow nanofibers are 350.7 and 4201.5 to 50 and 100 ppm H₂S at 250 °C, which are over 20 and 140 times higher than those of pristine In₂O₃ hollow nanofibers, respectively. Moreover, the corresponding sensor exhibits excellent selectivity and good reproducibility towards H₂S, and the response of 6%Cu-In₂O₃ is still 1.5 to 1 ppm H₂S. Finally, the gas sensing mechanism of Cu-In2O3 hollow nanofibers is thoroughly discussed, along with the assistance of first-principles calculations. Both the formation of hollow structure and Cu doping contribute to provide more active sites, and meanwhile a little CuO can form p–n heterojunctions with In₂O₃ and react with H₂S, resulting in significant improvement of gas sensing performance. The Cu-In₂O₃ hollow nanofibers can be tailored for practical application to selectively detect H₂S at lower concentrations.