Structure evolution and microwave absorption properties of nickel nanoparticles incorporated carbon spheres

Abstract Carbon spheres were obtained by hydrothermal synthesis using glucose as carbon source, and then nickel nanoparticles were incorporated on carbon spheres by reducing with hydrogen. The nickel nanoparticles (about 6 nm) with magnetic loss were uniformly dispersed on the surface of carbon spheres (200–400 nm) with dielectric loss. The few-layer graphene have been obtained on the carbon spheres by nickel catalysis. The minimum reflection loss value of −20.3 dB was observed at 14.4 GHz with a matching thickness of 9.0 mm for 40 wt.% composites. The nickel nanoparticles incorporated carbon spheres are a promising candidate for excellent microwave absorption materials.