Journal
ADVANCED FUNCTIONAL MATERIALS
Volume -, Issue -, Pages -Publisher
WILEY-V C H VERLAG GMBH
DOI: 10.1002/adfm.202304442
Keywords
Co clusters; electromagnetic wave absorbing mechanism; nitrogen-doped graphene; single-atom Co; synergistic effect
Ask authors/readers for more resources
By controlling the concentration of copper atoms, the dipole polarization and relaxation of the copper atoms can be adjusted, thus achieving optimized dipole moments and excellent absorption performance.
It is very challenging to demonstrate the intrinsic feature and absorption mechanism for electromagnetic (EM) wave absorber since dipole polarization loss is always discussed together with magnetic loss, conductive loss, defects/interfacial polarization, and so on. To address this issue, here, a kind of atomic composites is reported, including single-atom Co and Co cluster with controllable atom dipole to tune the polarization and establish the link between dipole polarization and the EM wave absorption. Using a chemical synthesis route, the atomic composites are fabricated, including Co single-atom (SA) sites and cluster (Cs) on nitrogen-doped graphitic carbon (Co1+Cs/NGC). Due to the special design, the effect of magnetic loss, conductive loss, and interfacial polarization on EM wave dissipation can be ignored so that it can only highlight dielectric loss caused by dipole polarization. And, by controlling the Co atoms concentration, it can tune the valence state of Co atoms between 0 to +2 to control dipole polarization and relaxation. As a result, the Co1+Cs/NGC-2 with Co concentration of 6.0 wt% exhibits optimized dipole moments and thus excellent absorption performance (the reflection loss exceeds -54.3 dB, and the effective absorption bandwidth with RL <=-10 dB reaches 7.0 GHz at 2.0 mm) due to the effective dipole polarization caused by the large annular dipole bounded between Co SA sites and Co Cs. This study proposes a simplified model to clarify EM wave absorption mechanism from atom view.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available