## 3 EMA and Flame-Retardant Dual-Functional MOF Composites  
### Fe-Mof  
In recent years, Fe-based MOFs have shown great potential in the fields of EMA and flame retardancy due to their tunable microstructures and excellent functional properties [75; 76]. [PERSON] et al. [77] used a simple one-pot solvothermal synthesis approach to develop Fe-MOFs on the surface of in situ reduced graphene oxide (rGO), resulting in a unique Fe-MOF-rGO microwave absorber. When the Fe-MOF-rGO content reached 25 wt.% and the thickness was 2.0 mm, the RL\({}_{\text{min}}\) reached \(-43.6\) dB, and the EAB exceeded 5.0 GHz, meeting the high-efficiency, lightweight, and wide-bandwidth requirements. Furthermore, the addition of 10 wt.% Fe-MOF-rGO into EP resulted in 42.1%, 42.3%, and 17.7% reductions in heat release capacity (HRC), pHRR, and THR, demonstrating excellent flame retardancy.  
The flexible coordination between phosphate groups and metals gives metal-based phosphates a variety of electronic structures and electronic conduction pathways, giving them distinct dielectric responses and impedance matching characteristics. Furthermore, metal-based phosphates demonstrate excellent high-temperature and fire-resistant performance [78; 79]. Therefore, developing metal-based phosphate/doped heteroatom carbon composites has promise for producing highly efficient and controllable EMA and flame retardancy. [PERSON] et al. [80] prepared fire-resistant Fe-based phosphate-/phosphorus-doped carbon composites by annealing phytic acid-treated MIL-101(Fe) as the precursor. By varying the amount of phytic acid during the preparation process, they were able to obtain the Fe\({}_{2}\)P\({}_{4}\)O\({}_{12}\)/phosphorus-doped carbon (Fe\({}_{2}\)P\({}_{4}\)O\({}_{12}\)/P-C) composite with the best EMA performance, achieving an EAB of 5.76 GHz (d = 2.1 mm) and an RL\({}_{\text{min}}\) of \(-67.6\) dB (d = 2.0 mm). Meanwhile, the Fe\({}_{2}\)P\({}_{4}\)O\({}_{12}\)/P-C composite showed good fire resistance. After 3 min of exposure to flame, composite sheets formed from the material retained their macroscopic shape.  
MOF-derived materials for EMA composites have garnered extensive attention due to their unique structural design flexibility and excellent functional properties. [PERSON] et al. [81] created a MOF-derived Fe/C/carbon foam (Fe/C/CF) 3D magnetic composite EMA material by using carbon foam as a template and uniformly distributing Prussian blue nanocubes throughout the carbon foam skeleton (Figure 2a). The Fe/C/CF achieved a RL\({}_{\text{min}}\) of \(-66.7\) dB and the maximum EAB of 6.34 GHz, as shown in Figure 2b,c. Furthermore, the hybrid foam's surface temperature remained nearly unchanged when heated for more than 1 h at a constant 120 \({}^{\circ}\)C, demonstrating its excellent thermal insulation performance (Figure 2f). Additionally, since heat-emitting devices are easily detectable by infrared cameras, military equipment requires infrared stealth capability. As illustrated in Figure 2d, the hybrid foam is the same hue as the surroundings, suggesting that the heated hand's infrared stealth has been achieved. Similarly, the target of military equipment concealed with hybrid foam is undetectable to the thermal infrared camera (Figure 2e).