Physics

Geology

Carbonization

Nanotechnology

Reflection loss

Mathematics

Porosity

Biomass (ecology)

Composite number

Absorption (acoustics)

Porous medium

Oceanography

Nanopore

Mathematics education

Engineering

Carbon fibers

Microscale chemistry

Composite material

Materials science

Scanning electron microscope

Nano-

Microwave

Quantum mechanics

Chemical engineering

ACS Applied Materials & Interfaces

A variety of biomass-based carbon materials with two-level porous structure have been successfully prepared by one-step carbonization process. The first level of microscale pores templates from the inherent porous tissues, while the second one of nanopores is produced by the in situ etching by the embedded alkaline metal elements. The superimposed effect of nano and microscale pores endows the hierarchically porous carbons (HPCs) with excellent microwave absorption (MA) performance. Among them, the spinach-derived HPC exhibits a maximum reflection loss of -62.2 dB and a broad effective absorption bandwidth of 7.3 GHz. Particularly, this excellent MA performance can be reproduced using the biomass materials belonging to different families, harvested seasons, and origins, indicating a green and sustainable process. These encouraging findings shed the insights on the preparation of biomass-derived microwave absorbents with promising practical applications.

Hierarchically Porous Carbons Derived from Biomasses with Excellent Microwave Absorption Performance