Fig. 1. TEM images of ZIF-67 and Co/C composites prepared by different power laser irradiation. (a) TEM image of ZIF-67;(b)-(f) TEM images of Co/C composites prepared by 15, 25, 35, 45, and 55 mW laser irradiation on ZIF-67 precursor

Fig. 2. XRD spectra and XPS for Co/C composites prepared by 15, 25, 35, 45, and 55 mW laser irradiation. (a) XRD spectra; (b) XPS

Fig. 3. Complex permittivity and permeability in the frequency range of 2-18 GHz for Co/C composites prepared by 15, 25, 35, 45, and 55 mW laser irradiation. (a)-(c) Real part, imaginary part, and tan δ_E of complex permittivity; (d)-(f) real part, imaginary part, and tan δ_μ of complex permeability

Fig. 4. Reflection loss of ZIF-67 and Co/C composites prepared by laser irradiation under different power. (a) ZIF-67; (b) 15 mW; (c) 25 mW; (d) 35 mW; (e) 45 mW; (f) 55 mW

Fig. 5. Electromagnetic loss mechanisms of Co/C composites. (a)-(e) Cole-Cole semicircle curves of Co/C composites prepared by ZIF-67 under 15, 25, 35, 45, and 55 mW laser irradiation; (f) C₀ value of the five samples

Fig. 6. Electromagnetic wave attenuation ability and impedance matching of Co/C composites prepared by laser irradiation under different power. (a) Attenuation constant; (b) impedance matching