The development of microwave absorption materials (MAMs) is a considerable important topic because our living space is crowed with electromagnetic wave which threatens human’s health. And MAMs are also used in radar stealth for protecting the weapons from being detected. Many nanomaterials were studied as MAMs, but not all of them have the satisfactory performance. Recently, metal–organic frameworks (MOFs) have attracted tremendous attention owing to their tunable chemical structures, diverse properties, large specific surface area and uniform pore distribution. MOF can transform to porous carbon (PC) which is decorated with metal species at appropriate pyrolysis temperature. However, the loss mechanism of pure MOF-derived PC is often relatively simple. In order to further improve the MA performance, the MOFs coupled with other loss materials are a widely studied method. In this review, we summarize the theories of MA, the progress of different MOF-derived PC‑based MAMs, tunable chemical structures incorporated with dielectric loss or magnetic loss materials. The different MA performance and mechanisms are discussed in detail. Finally, the shortcomings, challenges and perspectives of MOF-derived PC‑based MAMs are also presented. We hope this review could provide a new insight to design and fabricate MOF-derived PC-based MAMs with better fundamental understanding and practical application.
A high-quality
Fe3GeTe2 single crystal with
good electrical, magnetic, and electromagnetic wave absorption and
shielding properties was prepared in a large quantity (10 g level)
by solid-phase sintering and recrystallization method, which would
promote its in-depth research and practical application. It has good
room-temperature electrical properties with a mobility of 42 cm2/V·s, a sheet (bulk) carrier concentration of +1.64 ×
1018 /cm2 (+3.28 × 1020 /cm3), and a conductivity of 2196.35 S/cm. Also, a Curie temperature
of 238 K indicates the high magnetic transition temperature and a
paramagnetic Curie temperature of 301 K shows the large ferromagnetic–paramagnetic
transition zone induced by the residual short-range ferromagnetic
domains. Particularly, Fe3GeTe2 is in a loosely
packed state when used as a loss agent; the electromagnetic wave absorption
with a reflection loss of −34.7 dB at 3.66 GHz under thin thickness
was shown. Meanwhile, the absorption band can be effectively regulated
by varying the thickness. Moreover, Fe3GeTe2 in a close-packed state exhibits terahertz shielding values of 75.1
and 103.2 dB at very thin thicknesses of 70 and 380 μm, and
the average shielding value is higher than 47 dB, covering the entire
bandwidth from 0.1 to 3.0 THz. Furthermore, by using Fe3GeTe2 as a patch, the wideband radar cross-section can
be effectively reduced by up to 33 dBsm. Resultantly, Fe3GeTe2 will be a promising candidate in the electromagnetic
protection field.
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