Biomimetic "capillary" architecture engineered through biomass-derived carbon nanotubes aerogel for electromagnetic wave absorption and noise control

Biomass-derived aerogels are experiencing rapid development in electromagnetic protection due to their lightweight nature, controllable fabrication, and multifunctionality. However, designing simple structural strategies for biomass-based aerogel components to achieve high-performance electromagnetic wave absorption (EWA) materials with broad effective absorption bandwidth (EAB) and strong absorption remains a challenge. This work successfully fabricated cellulose/chitosan/carbon nanotube aerogels (CCCA) via a facile freeze-drying method. A capillary-like architecture constructed at the micro-nano scale enabled optimal impedance matching through balanced conductive and polarization losses. The optimized CCCA demonstrated remarkable EWA performance with a minimum reflection loss ( RL min ) of -45.17 dB at 3.5 mm thickness and a broad EAB of 5.6 GHz at 2 mm thickness (covering nearly the entire Cu band). Additionally, the aerogel exhibited exceptional noise reduction capabilities. This high-performance, easily fabricated biomass-derived aerogel integrates lightweight properties, noise suppression, and microwave absorption, demonstrating promising application prospects in electromagnetic shielding, electronic devices, and aerospace engineering.