A novel synthesis method of magnetic porous carbon composites for microwave absorption

A novel combined process of sol-gel method and subsequent in-situ pyrolysis was proposed to prepare magnetic porous carbon composites. Wheat flour was used as the raw material to prepare porous carbon matrix, and three composites doped with different magnetic metals (Co, Ni and Fe20Ni80) were prepared through adding different metal salts to wheat flour. The three composites show similar morphologies and are composed of porous carbon matrix and magnetic metal particles embedded in the matrix. Porous carbon matrix optimizes impedance matching and provides dielectric loss and multiple reflection and diffraction loss to incident electromagnetic waves. Magnetic metal particles endow the composites with ferromagnetic characteristics and magnetic loss ability. The three composites all exhibit outstanding microwave absorption performance and have the potential to become microwave absorbing materials.