Impact of Fe deposition on microwave absorption properties of ordered mesoporous carbon flakes

Abstract

Lightweight ordered mesoporous carbon (OMC) flakes have been successfully synthesized by an evaporation-induced self-assembly route. The highest specific surface area and pore volume of the OMC flakes reach 1727 m2 g−1 and 2.05 cm3 g−1, respectively. The results of the complex permittivity show the OMC/paraffin composites have high dielectric loss in the frequency range of 2–18 GHz. In order to enhance the microwave absorption properties of the OMC materials, an electroless plating method is exploited to deposit Fe particles on the OMC flakes. Benefiting from the magnetic loss and improved impedance characteristic, the OMC/Fe composites display excellent microwave absorption properties. The minimum reflection loss of the OMC-700-Fe composite reaches −\u200965.3 dB at 10.1 GHz and the absorption bandwidth <\u2009−\u200910 dB is up to 4.7 GHz (8.7–12.4 GHz) with the absorbing thickness of 2.5 mm. When the thickness is from 1.8 to 5.5 mm, all of the peak values of reflection loss are <\u2009−\u200920 dB. This work provides a new opportunity for the fabrication and design of lightweight microwave absorbers.