Biomimetic nacre-inspired brick and mortar architecture of PCGN aerogel for microwave absorption

In the field of wave absorption, balancing impedance matching and attenuation capability remains challenging. Inspired by the layered structure of abalone shells, this study fabricated the polyacrylonitrile/carbon nanotube/graphene/nickel (PCGN) composite aerogel with a nacre-like "brick and mortar" architecture through hydrothermal reduction and freeze-drying method. By optimizing the RGO/CNTs ratio, a multi-scale conductive network and hierarchical porous structure was constructed, which exhibited excellent impedance matching and electromagnetic wave attenuation. This doped structure enables regulation of the material's dielectric parameters, preventing excessively high or low impedance matching. The optimized porous architecture induces multiple heterogeneous interface advantages, facilitating high electromagnetic attenuation mechanisms and enabling the aerogel to demonstrate broad-band microwave absorption. The optimal sample (PCGN-3) achieved a reflection loss of -51.73 dB at 2.5 mm thickness with an effective absorption bandwidth of 6.48 GHz, covering the entire Ku band. The aerogel also exhibits compelling compressive resilience (maintain 80% height retention after 50 cycles at 60% strain), thermal insulation (surface ΔT < 10 °C between 50-125 °C) and infrared stealth performance, demonstrating its potential for application in complex industrial environments.