Research progress on nanostructure design and composition regulation of carbon spheres for the microwave absorption

Microwave absorbing material is a kind of material that can absorb microwave and electromagnetic (EM) energy and has less reflection and scattering. Qualified microwave absorbers can effectively prevent EM pollution and protect human health. This review briefly introduces the principles of microwave absorption (MA), more importantly, the research progress in the nanostructure design and composition regulation of carbon spheres (CSs) are reviewed. The nanostructure design is dominated by hollow and porous nature, and the composition regulation is based on conductive/dielectric, magnetic, as well as conductive/dielectric-magnetic components. Due to the synergistic effect among varieties of components and the clever nanostructure design, the CSs and their composites can achieve preferable MA performance than traditional carbon materials. At the same time, the challenges and prospects of the research on CSs are put forward, which provide new ideas for further study of microwave absorption based on CSs.