Bimetallic sulfides embedded into porous carbon composites with tunable magneto-dielectric properties for lightweight biomass- reinforced microwave absorber

Currently, biomass-derived porous carbon materials have great potential for the development of advanced microwave absorbing materials (MAMs) with lightweight, high performance, wide effective bandwidth (EAB), and thin matching thickness. Herein, we reported low-cost, high-performance MAMs for the successful anchoring of Cu-based bimetallic sulfides CuCo2S4@CoS2 on biomass porous carbon (BPC) derived from pistachio shells using a simple carbonization, hydrothermal, and electrostatic self-assembly method. The results demonstrate that the prepared BPC@CuCo2S4@CoS2 composite exhibits excellent microwave absorption due to its balanced impedance matching and the combined effect of conductive loss, dipole polarization, interfacial polarization, dielectric loss, and magnetic loss. To be precise, the minimum reflection loss (RLmin) of BPC@CuCo2S4@CoS2 reaches −64.2 dB at a packing load of 20 wt%, with an EAB of 6.6 GHz and a thickness of 2.3 mm. This work provides new insights into the study of copper-based bimetallic sulfide and BPC composites in MAMs.