Controllable synthesis of nitrogen-doped porous Fe3C@C nanocomposites for efficient microwave absorption

Three-dimensional (3D) porous carbon-based materials are commonly considered to be a hopeful microwave absorbing materials owing to their lightweight and broadband absorption. However, the structure between dissipation mechanism is still not clear. Therefore, in this work, the nitrogen-doped porous Fe 3 C@C nanocomposites derived from Fe(NO 3 ) 3 ·9 H 2 O and polyvinyl pyrrolidone (PVP) were fabricated through pre-blowing followed by in situ carbonization method with various temperatures. The obtained material treated at 600 °C, which the content of N was 4.07 %, exhibits the most excellent microwave absorption (MA) property with the minimal reflection loss of − 63.1 dB at 5.0 GHz while the matching thickness is 4.6 mm. The MA performance of the composite is originated from the synergy of magnetic-dielectric loss and improved interfacial polarization. This research provides a way to prepare high-property MA absorbers.