To efficiently decrease ablation heat accumulation and improve the ability of ZrC–SiC/TaC coatings to protect carbon/carbon (C/C) composites, a thermally conductive nanonetwork with a ceramic@carbon core–shell structure was designed and constructed. Polymer-derived SiC/TaC with a graphene carbon shell was synthesized and introduced into a ZrC coating by supersonic atmospheric plasma spraying (SAPS). Graphene shell paths increased the heat transfer capability by lowering the surface temperature to approximately 200 °C during oxyacetylene ablation. The heat dissipation of the graphene shell in the ZrC–SiC/TaC@C coating reduced the volatilization of low-melting-point phases and delayed the sintering of ZrO₂ particles. Thus, the graphene shell in ZrC–SiC/TaC@C coating decreased the mass and linear ablation rates by 91.4% and 93.7% compared to ZrC–SiC/TaC coating, respectively. This work provided a constructive idea for improving the ablation resistance of the coatings by incorporating carbon nanomaterials as a function of heat dissipation.

Core–shell structured SiC@SiO₂ nanowires and Si@SiO₂ nanowires were prepared on the surface of carbon/carbon (C/C) composites by a thermal evaporation method using SiO powders as the silicon source and Ni(NO₃)₂ as the catalyst. The average diameters of SiC@SiO₂ nanowires and Si@SiO₂ nanowires are about 145 nm, and the core–shell diameter ratios are about 0.41 and 0.53, respectively. The SiO₂ shells of such two nanowires resulted from the reaction between SiO and CO and the reaction of SiO itself, respectively, based on the model analysis. The growth of these two nanowires conformed to the vapor–liquid–solid (VLS) mode. In this mode, CO played an important role in the growth of nanowires. There existed a critical partial pressure of CO (p_C) determining the microstructure evolution of nanowires into whether SiC@SiO₂ or Si@SiO₂. The value of p_C was calculated to be 4.01×10⁻¹⁵ Pa from the thermodynamic computation. Once the CO partial pressure in the system was greater than the p_C, SiO tended to react with CO, causing the formation of SiC@SiO₂ nanowires. However, the decomposition of SiO played a predominant role and the products mainly consisted of Si@SiO₂ nanowires. This work may be helpful for the regulation of the growth process and the understanding of the growth mechanism of silicon-based nanowires.