Atom-economical construction of three-dimensional macroporous ternary MoC/Co/C aerogels for advanced electromagnetic wave dissipation

The integration of multiple components is prevalent strategy for designing high-performance electromagnetic wave absorbing materials (EWAMs), while such an approach often complicates structural design, particularly in aerogel construction, which still relies on tedious and time-consuming processing methods. Herein, we demonstrate a simple and atom-economical strategy that leverages the foaming characteristics of polyvinylpyrrolidone for the fabrication of ternary MoC/Co/C aerogels, without generating any solid or liquid waste. The formation mechanism of ternary aerogels has been systematically analyzed, where the synergy between cobalt nitrate (CN) and ammonium molybdate (NM) intensifies the foaming process to realize higher porosity. The dosage of NM can tunably regulate the relative compositions of these aerogels, and also regulate their EM properties effectively. After blending with paraffin (organic binder), the mixture that contains FMCC-10 (NM dosage: 0.10 g) exhibits the best EM absorption performance, whose strongest reflection loss reaches up to −78.5 dB and an effective absorption bandwidth below −10.0 dB achieves 6.0 GHz with the thickness of merely 1.80 mm. Its performance outperforms many reported homologous ternary composites and some graphene-based aerogels. EM analyses confirm that the good performance benefits from decent loss ability and impedance matching created by the appropriate composition and unique aerogel microstructure. Computer simulation technology (CST) simulations and periodic metamaterials designs further demonstrate their great potential as lightweight and broadband EWAMs in practical application.