Macropore engineering of MOF-derived carbon for superior microwave absorption

Regulating electromagnetic pollution has become significance as 5G communication and radar technologies rapidly progress. This study proposes a macroporous engineering method utilizing polystyrene microsphere templates to address the limitations of single pore size structure and the difficulties in achieving impedance matching and loss capability in traditional carbon materials derived from metal-organic frameworks (MOFs). Co-Zn-C/C composite materials with a multi-level pore structure have been successfully synthesized. Through meticulous regulation of the PS template's dimensions via PVP dosage modifications, Metal-organic framework-on-Metal-organic framework (MOF-on-MOF) epitaxial growth, and a high-temperature carbonization of ZIF-8/ZIF-67, a composite material featuring a multi-level pore architecture (macropore mesoporous carbon nanotube network) and tunable pore size was synthesized. The results indicate that the material contains uniformly dispersed Co nanoparticles, a substantial specific surface area, and many nitrogen-doped defects. The optimized CZCC-2 sample demonstrates superior impedance matching and multi-mechanism synergistic attenuation, achieving an effective absorption bandwidth of 6.59 GHz at a thickness of 2.1 mm and a minimum reflection loss of -59.48 dB at 9 GHz at 3.0 mm, as per electromagnetic performance testing. The exceptional capability for suppressing electromagnetic wave scattering in practical applications is further validated by finite element modeling and radar cross-section (RCS) analysis. This paper presents innovative methods for developing absorbent materials that are thin, lightweight, broadband, high-intensity.