Coral-like carbon-based composite derived from layered structure Co-MOF-71 with outstanding impedance matching and tunable microwave absorption performance

Large Microsphere Structure of a Co/C Composite Derived from Co-MOF with Excellent Wideband Electromagnetic Microwave Absorption Performance

“…Two peaks at 780.4 and 778.5 eV match to Co 2p 3/2 , while two peaks at 793.6 and 795.7 eV match to Co 2p 1/2 . Furthermore, the satellite peak at 803 eV matches to Co 2p 1/2 . ,, …”

“…The image between ε″ and ε′ looks like a semicircle; it is commonly regarded as a Cole–Cole semicircle, which represents a Debye relaxation process. , Panels a–d of Figure show that all of the curves of T1, T2, T3, and T4 have multiple semicircles; this suggests the existence of multiple Debye relaxation processes within the composites. The Cole–Cole semicircles of the composites are irregular, indicating that there are multiple dielectric loss mechanisms inside the Co/C composite, such as Maxwell Wasgner relaxation. , Furthermore, each Cole–Cole semicircle curve contains an approximately straight-line part, demonstrating the existence of conduction losses within the four Co/C composites. More importantly, the curve of T2 has significantly more Cole–Cole semicircles than the other three composites, indicating that T2 has more Debye relaxation process and loss mechanisms, which may also contribute to improving the absorption performance.…”

“…The capability of a material to attenuate EMW is commonly quantified by means of reflection loss (RL), with a smaller RL value signifying a larger attenuation capacity. For instance, if the RL value remains below −10 dB, then approximately 90% of the EMW is able to be attenuated. , Microwave absorption (MA) materials are widely used in medical protection, where higher requirements are also imposed on them. − Ideal MA materials need to meet four aspects, including “thin thickness, lightweight, wide bandwidth, and strong absorption”. − …”

Review and Perspective of Tailorable Metal‐Organic Framework for Enhancing Microwave Absorption

“…Except for hollow, core‐shell, and yolk‐shell structures, MOF precursors can assemble abundant microstructures, such as hierarchical interfacial structures, coral‐like carbon‐based composite, [ 214 ] nanofiber, [ 215 ] plum‐like NiCo@C composite, [ 216 ] hexagonal nanoflakes, [ 217 ] concave cube nanocomposite, [ 218 ] flower‐like nickel and carbon composites, [ 219 ] and pearl necklace‐like CoMn‐ based nanostructures, etc . [ 220 ] The detailed microwave absorption data are illustrated in Table 2.…”

A Mini-Review on Recent Developments in Metal-Organic-Frameworks (MOFs) Derived Carbon as A Microwave Absorption Materials (MAMs)

“…Representative materials to the Magnetic loss mechanism are ferrite, magnetite, magnetic compounds and metals, and others. Conversely, the higher observed density and relatively lower stability restricted their experimental applications [8]. Fe, Co, and Ni are three of the most common magnetic metals on the market.…”