High-efficiency and wide-bandwidth microwave absorbers based on MoS2-coated carbon fiber

Enabling highly efficient and broadband electromagnetic wave absorption by tuning impedance match in high-entropy transition metal diborides (HE TMB2)

“…In this light, TMB 2 with good thermal stability, oxidation and corrosion resistance, and good dielectric loss capability are promising as EM wave absorbing materials. However, akin to the foregoing dielectric loss-type absorbers, the conductivity of TMB 2 is too high that a continuous conduction current is formed at the surface, which leads to poor impedance match and inferior EM wave absorption performance [6,7]. As demonstrated by Jian et al [34], the reflection loss (RL) values of pure ZrB 2 are larger than −5 dB within the thickness of l-5 mm in the frequency range of 2-18 GHz.…”

“…To date, a bunch of EM wave absorbing materials based on dielectric loss or magnetic loss mechanism have been developed. For instance, dielectric loss-type absorbers include carbon fiber (CF) [6], carbon nanotube (CNT) [7], reduced graphene oxide (rGO) [8], conductive polymer [9], oxides (silicon oxide [10], zinc oxide [11], etc. ), transition metal sulfides [12], silicon carbide [13], and 2D transition metal carbides/ nitrides/carbonitrides (MXenes) [14], and magnetic loss-type absorbers consist of ferrites [15][16][17] and magnetic metals [18][19][20].…”

“…Although dielectric loss-type EM absorbing materials exhibit high attenuation constant (α) mainly derived from dielectric loss, they are still hindered by limited absorption capacity and narrow effective absorption bandwidth (EAB) due to the mismatch between the complex permittivity and the complex permeability. In specific, highly conductive materials tend to form conductive framework at the surface and result in skin effects, which prevent the EM waves from penetrating into materials and reduce the occurrence of multi-attenuations [6,7]. As for magnetic loss-type absorbers, they take advantages of a proper magnetization value and a relatively high Curie temperature but also suffer from a sudden decrease of permeability in high frequency due to the Snoek's limit [16,21,22].…”

“…As for magnetic loss-type absorbers, they take advantages of a proper magnetization value and a relatively high Curie temperature but also suffer from a sudden decrease of permeability in high frequency due to the Snoek's limit [16,21,22]. Hence, various efforts have been carried out to realize dielectric and magnetic losses coupling and impedance matching, which can be achieved through composite construction [6,16,[23][24][25], elemental doping [10], and structural design [26,27]. Although impedance match can be effectively achieved by the foregoing methods, complex experimental procedures and difficulties in accurately controlling nanostructures and interfaces are still unignorable issues.…”

MoS2 nanoparticle/activated carbon composite as a dual-band material for absorbing microwaves

“…Generally, a pure dielectric absorber faces with the problem of poor impedance matching 2 , but in recent reported studies, various carbon-based materials has been combined with MoS 2 and showed that a dielectric absorber can also give enhanced MW absorbing performance. Like MoS 2 coated carbon fiber fabricated by Zhang et al 10 gave an excellent EAB of 10.85 GHz. The MoS 2 /Carbon Nanotubes (CNTs) (2D/1D) composite synthesized by Sun et al gave a maximum EAB = 5.60 GHz (RL max = -47.9 dB) 11 .…”