ZnCo-MOF derived porous ZnO/Co/C composites as superior electromagnetic wave absorbers

The ZnO/Co/C composite materials, consisting of ZnO and ferromagnetic Co embedded in a carbon skeleton were successfully synthesized through the pyrolysis of a ZnCo-MOF precursor. The evolution of phase and microstructure was systematically investigated. The results indicate that the EMW absorption performance is dependent on the degree of graphitization and phase compositions. When the precursor pyrolysis temperature is 800 ℃, the ZnO/Co/C composites benefiting from the synergistic effect of constituents and microstructure demonstrate exceptional EMW absorption performance, with a minimum reflection loss (RL_min) of -52.2 dB at 11.5 GHz and a sample thickness of 2.23 mm. The widest effective absorption bandwidth (EAB) harvests 6.7 GHz (11.3-18 GHz) with a sample thickness of 2 mm, encompassing the entire Ku band. Herein, this study shed light on exploring high-efficiency MOF-based EMW absorption materials with rational design of components and structure, and the as-prepared ZnO/Co/C composites are potential candidates for EMW absorption applications.