MOF-derived C/SiOC ceramic aerogels with high strength and excellent microwave absorption performance

Area of Science:

• Materials Science
• Nanotechnology
• Ceramic Engineering

Background:

• Advanced materials are needed for effective electromagnetic wave (EMW) absorption and thermal management.
• Metal-Organic Frameworks (MOFs) offer tunable precursors for novel ceramic composites.

Purpose of the Study:

• To synthesize novel C/SiOC composite aerogels with enhanced EMW absorption, mechanical strength, and thermal insulation.
• To investigate the catalytic role of Zn/Co species in carbon graphitization and dielectric loss.
• To explore the impact of heterointerfaces on polarization relaxation and scattering for EMW attenuation.

Main Methods:

• Synthesis of MOF-derived C/SiOC composite aerogels using a polymer-derived ceramic (PDC) route.
• Utilizing Zn/Co species as catalysts to control carbon structure and graphitization.
• Characterization of material properties including EMW absorption, mechanical robustness, and thermal conductivity.

Main Results:

• Achieved exceptional EMW absorption with a minimum reflection loss (RLmin) of -62.5 dB and an effective absorption bandwidth (EAB) of 5.32 GHz.
• Demonstrated robust mechanical properties with a compressive strength of 54 MPa.
• Exhibited excellent thermal insulation with a thermal conductivity of 0.346 W m⁻¹ K⁻¹.
• Zn/Co catalysts facilitated conductive networks and defective carbon, enhancing dielectric loss.

Conclusions:

• The developed C/SiOC composite aerogels exhibit superior multifunctional performance for EMW absorption and thermal insulation.
• The PDC route and catalytic approach are effective for designing advanced SiOC-based materials.
• These materials are suitable for demanding applications in extreme environments requiring EMW attenuation and thermal management.