Supramolecular self-assembly derived Mo2C/FeCo/NC hierarchical nanostructures with excellent wideband microwave absorption properties

Developing highly efficient electromagnetic wave absorption materials with tunable properties has been attracting extensive concern for tackling severe electromagnetic pollution. Composition and microstructure of absorber are two determinative factors for properties. Herein, we proposed supramolecular self-assembly combined with carbonization strategy to construct hierarchical carbon molybdenum/iron-cobalt alloy/nitrogen doped carbon (Mo2C/FeCo/NC) nanocomposites. By adjusting pH values and the kinds of surfactants, the nanostructures with flower shaped balls, lily clusters and bowknots morphologies were obtained. The highly dispersed Mo2C nanoparticles could induce multilevel heterostructural interfaces and enhance absorption peculiarity for carbon-based materials. The FeCo nanoparticles could produce strong magnetic coupling networks to improve synergy effect. Impressively, the as-synthesized optimal sample (8.5-Mo2C/FeCo/NC) exhibited superior electromagnetic wave absorption performances with the maximum reflection loss (RL) value of −56.03 dB and wide effective absorbing bandwidth of 10.27 GHz at 3.4 mm matching thickness, meanwhile, the effective absorption area was up to 135.57 (dB GHz). In addition, the RL of anion-Mo2C/FeCo/NC was up to −60.18 dB with the matching thickness of 2.8 mm, and the maximum RL of the cation-Mo2C/FeCo/NC composites reached up to −77.37 dB at 2.2 mm. Remarkably, even if at the thickness of 2.2 mm, the effective bandwidth of 7.25 GHz could be obtained. The excellent absorbing performance was attributed to 3D carbon conductive network, favorable dipolar/interfacial polarization, natural resonance/eddy current effect, multiple reflection and scattering, and satisfied impedance matching. Thus, this work may pave new avenues for designing high-performance and lightweight absorbing materials.