Novel accordion-like structure of SiC/C composites for enhanced electromagnetic wave absorption

Two-dimensional (2D) composites have been identified as a rising star in the exploration of efficient electro-magnetic wave (EMW) absorbers due to their structural designability and tunable dielectric constants. However, how to address the high filling rate of absorbers with 2D microstructures and the easy stacking problem between layers remain difficult and painful points. Inspired by the adjustable spacing of expanded graphite layers, it is rationally proposed to prepare unique and novel 2D accordion like SiC/C composites by microwave-assisted method and carbothermal reduction strategy. The microstructural modification and multicomponent modulation are achieved by regulating the carbothermal reduction temperature. The results confirm that the presence of plentiful inhomogeneous interfaces in 2D accordion like SiC/C composites, the enhanced dipole polarization, the improved conductive loss due to the unique 2D accordion like structure endow carriers with more paths, and the optimized impedance matching due to the porous structure synergistically result in superior EMW absorption properties. 2D accordion like SiC/C-2 exhibits a minimum reflection loss of-54.52 dB at 8.72 GHz with an ultra -low fill rate of 3%, and the effective absorption range covers 11.40 GHz (7.60-18 GHz) at a total thickness of 1.20 mm (1.23-2.43 mm), which is 71.25% of the whole range of frequencies. Additionally, radar cross section (RCS) simulations verify that 2D accordion like SiC/C-2 can dissipate more EMW in a real environment. This work provides a reference for the rational construction of novel high-performance 2D structural absorbers.