Porous N-doped C/VB-group VS2 composites derived from perishable garbage to synergistically solve the environmental and electromagnetic pollution

The cooperative solution to environmental pollution and electromagnetic pollution is a big problem in environmental governance. Herein, N-doped C/VB-group flower-like VS2 composites were prepared using waste soybean husks recovered from the vegetable market as raw material through ordinary carbonization and hydrothermal method. The distinctive honeycomb-like porous structure of soybean husk contributes to multiple scattering and reflection and builds an interconnected conductive network. In addition, the presence of VS2 enriches the loss mechanism and significantly modulates the electromagnetic parameters of the composite material, generating a strong attenuation capability and ideal impedance matching. As a result, the composites exhibit an excellent electromagnetic wave (EMW) absorption performance with an ultra-low reflection loss (RL) value of −62.74 dB at a thickness of only 1.70 mm, and the effective absorption bandwidth (EAB) is up to 6.04 GHz (covering the entire Ku-band). The radar cross section (RCS) simulation further demonstrates the effectiveness of the composites in dissipating EMW (-6.69 dB m2 at 0°) in actual applications. The results showed that the C/VS2 composites have excellent EMW absorption performance, realized the reuse of waste soybean husks with high added value, and made it possible to solve electromagnetic pollution and environmental pollution together. Particularly, the dielectric sum-quotient model was further validated. It is crucial for nonmagnetic materials to modulate the sum and quotient of the real and imaginary parts of their dielectric constants to obtain excellent EMW absorption performance.