Microwave

Quantum mechanics

Calcination

Catalysis

Magnetic field

Composite number

Engineering

Materials science

Coating

Impedance matching

Absorption (acoustics)

Biochemistry

Chemical engineering

Giant magnetoimpedance

Porosity

Electrical impedance

Physics

Reflection loss

Nanotechnology

Magnetoresistance

Microstructure

Composite material

Chemistry

Giant magnetoresistance

Optoelectronics

Electrical engineering

Journal of Material Science and Technology

Metal-organic frameworks (MOFs) are considered as a novel type of microwave absorption (MA) material owing to the sufficient pore structure, diverse configurations, and easy-to-control magnetic properties. However, their evolution is limited by the imperfect impedance matching conditions caused by the undesirable microstructure. Herein, two types of novel porous coral-like carbon/Co3O4 and carbon/Co composites have been effectively fabricated for the first time by a facile heat treatment process of precursor Co-MOF-71. The graphitization degree, magnetic property and MA ability of the product can be effortlessly tuned by altering the heat treatment temperature of Co-MOF-71. Remarkably, S500 (Co-MOF-71 calcined at 500 °C) composite displays strong and multi-frequency absorption performance, whose minimum reflection loss (RL) value achieves -36.4 dB with an absorbing thickness of 3.0 mm and attains an effective absorbing bandwidth (RL≤-10 dB) of 5.76 GHz (almost covers whole Ku band) at a thinner coating thickness of 2.5 mm. Such superb MA ability has roots in the coral-like structure derived from the layer Co-MOF-71, sufficient electromagnetic loss. This work ameliorates the MA ability of MOFs through a special nanostructural design, which provides a fresh way for the preparation of novel MA materials.

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