SiCN/Al ₂ O ₃ ‐Reinforced N‐rGO Aerogels With Interpenetrating Networks for Thermal Insulation and Mechanical Robustness

ABSTRACT

Graphene aerogels are limited by poor high‐temperature stability and insufficient mechanical strength in harsh thermal environments. Herein, SiCN‐Al ₂ O ₃ dual ceramics were incorporated into a nitrogen‐doped reduced graphene oxide (N‐rGO) framework through hydrothermal self‐assembly, supercritical drying, and polymer‐derived ceramization to construct composite aerogels with nanoscale interpenetrating networks. At 20 wt% ceramic precursor, interconnected ceramic nanoparticles uniformly penetrated the N‐rGO sheets, forming a continuous and homogeneous architecture. The flexible graphene layers bridged rigid ceramic domains to dissipate stress and suppress crack propagation, while the ceramic network anchored the graphene sheets, inhibiting restacking and oxidation‐induced ablation. After pyrolysis at 1200°C, the optimized aerogel achieved a low thermal conductivity of 0.034 W m ⁻¹ K ⁻¹ , a yield strength of 0.92 MPa, and a two‐stage fracture behavior, demonstrating improved damage tolerance. This interpenetrating ceramic/graphene network enables lightweight aerogels with improved thermal insulation, oxidation resistance, and mechanical robustness.