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Page 2 of 10 Fan et al. Soft Sci 2024;4:43 https://dx.doi.org/10.20517/ss.2024.63

has become an urgent requirement. Ideal MAMs should possess excellent microwave absorption (MA)
properties, a wide effective absorption bandwidth (EAB), and be lightweight and thin [11-15] . Developed
MAMs can be broadly categorized into three groups: conductive polymers, conductive carbon matrices, and
magnetic materials [16-23] . While these materials are easy to prepare and relatively inexpensive, their single-
component nature often causes impedance mismatch, hindering development [24,25] . Therefore, integrating
carbon-based materials and metals in MAMs presents an effective solution to the challenges [26-28] .

Metal-organic frameworks (MOFs) consist of organic ligands and metal ions through coordination
interactions, and possess unique advantages of tunable structure, high porosity, good thermal stability, and
many metal coordination sites [29-31] . Therefore, they are often used as templates or precursors for MAMs, but
their low conductivity poses a challenge. The commonly used workaround is to carbonize MOFs at high
temperatures to synthesize porous carbon and metal or metal oxide composites with specific pore
structures, designed to create numerous defects, rich interfaces, and additional magnetic losses [32,33] .
Maintaining the morphology and porous structure of the original MOF can enhance multiple scattering and
reflection, which further promotes electromagnetic wave (EMW) dissipation . Additionally, MA
[34]
performance can be optimized by changing the types of organic ligands and metal ions to achieve a
combination of being “light, thin, wide and strong”.

Previous research has mainly focused on component regulation to design and develop MAMs by altering
metal ions or combining MOFs with other materials [35,36] . The dimensions and morphology of MOF-derived
materials also significantly influence their properties, making classification by dimension an effective
approach [Figure 1] [37-44] . Each dimension offers unique advantages: zero-dimensional (0D) materials have
abundant magnetic particles, one-dimensional (1D) materials form conductive networks, two-dimensional
(2D) materials possess excellent dielectric properties, and three-dimensional (3D) materials create
numerous heterogeneous interfaces. Thus, optimizing MA performance by adjusting precursor dimensions
[37]
and morphology is a promising research direction .
This paper systematically summarizes recent research progress on MOF-derived MAMs, including
morphological design, advantages, and MA characteristics. The electromagnetic response mechanism of
MAMs is elucidated. Finally, it discusses current challenges and future development prospects.

MAMS DERIVED FROM MOF
Core-shell and hollow structures are the prevalent morphological types in MOF-derived 0D structures. The
core-shell structure can form a rich heterogeneous interface to improve interface polarization, while the
hollow structure promotes multiple reflections and scattering of EMW. In the carbonization process,
graphitized carbon typically forms a carbon shell, and magnetic metal particles form a magnetic core,
facilitating the preparation of core-shell MOF derivatives. Wang et al. successfully prepared yolk-shelled
Ni@C@ZnO through the pyrolysis of a bimetallic Ni-Zn MOF precursor [Figure 2A] . Ni@C@ZnO has a
[40]
layered porous yolk-shell structure [Figure 2B and C]. During pyrolysis, ZnO nanosheets are formed
through the reaction of oxygen atoms with Zn , which are embedded into carbon matrices [Figure 2D]. The
2+
interfacial polarization and magnetic-dielectric synergistic effects contribute to the remarkable MA
performance of Ni@C@ZnO, with a minimum reflection loss (RL ) of -55.8 dB at a thickness of 2.5 mm.
min

MOF derivatives were prepared by directly carbonizing MOFs, which was also effective for the preparation
of hollow structures. Ma et al. synthesized MAMs with hollow bowl-like structures by straightforward
solvent heating and carbonation [Figure 2E and F] . The synergy of the dielectric and magnetic
[45]
components significantly optimizes impedance matching; the structure also has a large number of