1 research outputs found
MOFs-Derived Hollow Co/C Microspheres with Enhanced Microwave Absorption Performance
Rational
construction of a profitable microstructure in carbon-based
electromagnetic composites is becoming a promising strategy to reinforce
their microwave absorption performance. Herein, the microstructure
design is innovatively coupled with a metal–organic frameworks
(MOFs)-derived method to produce hollow Co/C microspheres (Co/C-HS).
The resultant composites combine the advantages of hollow microstructures
and good chemical homogeneity. It is found that the pyrolysis temperature
plays an important role in determining the electromagnetic properties
of these hollow Co/C microspheres, where high pyrolysis temperature
will increase relative complex permittivity and decrease relative
complex permeability. When the pyrolysis temperature is 600 °C,
the sample (Co/C-HS-600) will show improved impedance matching and
good attenuation ability, and thus an excellent microwave absorption
performance with strong reflection loss (−66.5 dB at 17.6 GHz)
and wide response bandwidth (over −10 dB, 3.7–18.0 GHz)
can be achieved. By comparing with Co/C composites derived from conventional
ZIF-67, it can be validated that a hollow microstructure is greatly
helpful to upgrade the performance by boosting dielectric loss ability
and suppressing a negative interaction between the carbon matrix and
incident electromagnetic waves, as well as providing multiple reflection
behaviors. We believe that this study may open a new avenue to promote
the electromagnetic applications of MOFs-derived carbon-based composites