Preparation of ZnO/Co/C/RGO Composites for Enhanced Microwave Absorption

ZnO/Co/C/reduced graphene oxide (RGO) composites are synthesized through carbonization of ZnCo-MOF-5/GO under an Ar/H₂ flow. The abundant active sites (e.g., functional groups and lattice defects), copious heterointerfaces (among Co, ZnO, C, and RGO), and wrinkled architecture trigger multiple dipole polarization, interface polarization, and enhanced conductive loss. By adjusting the content of RGO, the electromagnetic parameters for ZnO/Co/C/RGO composites were effectively regulated. The minimum reflection loss (RL_min) of ZnO/Co/C/RGO-50 composites is −52.72 dB at 1.70 mm, and the EAB is 3.57 GHz. Futhermore, CST simulation results further confirm the remarkable RCS reduction capacity for ZnO/Co/C/RGO-50 composites. The reduction value of RCS is 22.84 dB m², and effective absorption can reach the entire angle range. The superior microwave absorption property for ZnO/Co/C/RGO composites is benefited from cooperative action of dielectric loss (dipole polarization, interface polarization, conductive loss) and magnetic loss (natural resonance and exchange resonance).