Biomass-based carbon materials derived from Cyperus malaccensis Lam. var. brevifolius Bocklr with efficient microwave absorption performance

Compared with chemically synthesized materials, biomass materials often exhibit unique intrinsic structures, which can be utilized through optimizing microstructures and activation process to furnish low-cost and efficient Microwave Absorption Materials. This research uses a common hydrophyte (Cyperus malaccensis Lam. var. brevifolius Bocklr) in South China as the raw material to fabricate carbon-based biomass-derived absorbers through one-step synthesis. The fabricated carbon materials show efficient Microwave Absorption (MA) performance with minimum reflection loss (RLmin) of − 26.0 dB at 11.9 GHz from the sample pyrolyzed at 700 °C under the thickness of only 2 mm and wide effective absorption bandwidth of 4.6 GHz (11.6–16.2 GHz) from the sample annealed at 600 °C. Moreover, the effective MA bandwidth can cover the entire C to Ku band by tuning the thickness. A balance of dielectric loss mechanism and impedance matching is the reason why this biomass carbon-based absorber exhibits excellent MA performance. The results show that this biomass carbon has great potential to be low-cost, green and efficient carbon-based microwave absorbers.