Microwave

Quantum mechanics

Aerogel

Composite number

Engineering

Dielectric loss

Materials science

Absorption (acoustics)

Carbon fibers

Chemical engineering

Carbonation

Physics

Reflection loss

Carbon nanotube

Dielectric

Carbonization

Composite material

Scanning electron microscope

Optoelectronics

Composites Part B Engineering

Carbon aerogels derived from biomass have been considered as potential microwave absorption (MA) materials because of the intrinsic hierarchical porous structure, low density, and excellent heat resistance. However, high carbonation temperature or long carbonation time is always required to achieve optimized MA performance. Herein, the low-temperature carbonization of carbon nanotube (CNT)/cellulose aerogel was realized to develop a carbon aerogel for efficient MA. Compared with the carbon aerogel derived from pristine cellulose, the incorporation of CNT endowed the CNT/cellulose-derived carbon aerogel with improved dielectric loss, and thus improved MA performance at reduced carbonation temperature. The carbon aerogel carbonized at only 550 °C for 2 h exhibited a minimum reflection loss value of −43.6 dB and a broad effective absorption bandwidth (reflection loss below −10 dB) of 7.42 GHz. The low carbonation temperature and outstanding MA performance make this new carbon aerogel be promising candidate for MA applications.

Low-temperature carbonized carbon nanotube/cellulose aerogel for efficient microwave absorption