Facile synthesis of Co-embedded porous spherical carbon composites derived from Co3O4/ZIF-8 compounds for broadband microwave absorption

Carbon materials have extensive applications and research prospects as microwave absorbing materials, but their absorbing properties are limited by the lack of magnetic properties. Here, a simple grinding method was used to prepare the Co3O4/ZIF-8 precursor, and Co-embedded porous spherical carbon composites were obtained at high temperatures with enhanced microwave absorption performance. The additional magnetic performance from Co nanoparticles and formation of porous surface structure accounted for reinforced microwave absorption performance and broader electromagnetic absorption band. Consequently, as-prepared carbon composites demonstrated marvelous microwave absorption properties with an absorption capacity of 31.53 dB and a corresponding effective absorption bandwidth of 6.3 GHz. The simple and efficient preparation method simplifies the preparation of microwave absorbing materials, and has obtained encouraging achievements, paving the way for the development of high-performance porous microwave absorbing materials.