Enhanced electromagnetic wave absorbing nickel (Oxide)-Carbon nanocomposites

Abstract

Both NiO-carbon and Ni/NiO-carbon nanocomposites with a dual-configuration were successfully obtained via annealing nickel-carbon precursor under air and N2, respectively. For the NiO-carbon composites, the dual configurations were NiO nanoparticles incorporated in porous flower-like carbon materials and NiO nanoparticles anchored porous carbon microspheres. In the case of Ni/NiO-carbon composites, the dual configurations consisted of Ni/NiO nanoparticles distributed in the carbon flowers and Ni/NiO nanoparticles anchored on the porous carbon microspheres. Amazingly, an ultra-low amount (such as 2 wt%) of the NiO-carbon and Ni/NiO-carbon composites was introduced into the polyvinylidene fluoride (PVDF), the nanocomposites exhibited superior microwave absorption properties. The enhanced microwave absorption ability originated from the synergism consisting of dipole polarization, interfacial polarization, magnetic loss including natural resonance and exchange resonance, as well as dual-configuration contribution (impedance match, point discharge, multiple reflections and scattering). These PVDF nanocomposites filled with dual-configurations of NiO-carbon and Ni/NiO-carbon have been highlighted to be more competitive microwave absorbers in terms of lightweight, strong absorption and ultra-low filler amount.