Metal–organic framework derived cobalt phosphosulfide with ultrahigh microwave absorption properties

Nanostructure composites of ferromagnetic materials embedded in nanoporous carbon (NC) derived from metal–organic frameworks (MOFs) have attracted enormous attention due to their potential application in many fields, such as microwave absorption, energy storage, and conversion. The rational design of nanocomposites holds a determinant factor for overcoming the challenges involving the microwave absorption performance. Herein, CoS₂/NC, CoP/NC, and CoS_2−xP_x/NC with a rhombic dodecahedral structure have been successfully fabricated by using the template cobalt-based MOFs (ZIF-67). A morphology analysis indicates that ferromagnetic nanoparticles are embedded in NC matrix. It is obvious that the rhombic dodecahedron can be maintained after the phosphorization and sulfurization of Co/NC derived from the thermal decomposition of ZIF-67. The microwave absorption performance can obviously be improved by the phosphorization and sulfurization of Co/NC. CoS_2−xP_x/NC exhibits an excellent microwave absorption property and the minimum reflection loss (RL) of CoS_2−xP_x/NC can reach −68 dB at 14.6 GHz with a thickness of 1.5 mm. An RL value less than −10 dB can be achieved in the microwave frequency range of 12.7–17.3 GHz (4.6 GHz) with a thickness of 1.5 mm for CoS_2−xP_x/NC. This article offers a novel way to fabricate cobalt-based materials/carbon composites for an excellent microwave absorber. (paper)