Multi-components matching construction of α-[SiW11Mn(H2O)O39]6-/biacid co-doped polyaniline wrapped interstice skeletal NiCo2O4 for high-performance electromagnetic wave absorption

A highly effective electromagnetic wave absorber with great tunability of absorption strength and bandwidth, in which polyoxometalate anion alpha-[SiW11Mn(H2O)O-39](6-) and heteropoly acid cation/HCl co-doped polyaniline wrapped interstice skeletal NiCo2O4 (ISNiCo2O4@BCDPANI/alpha-[SiW11Mn(H2O)O-39](6-) nanocomposites), was successfully prepared via a facile hydrothermal combined with supramolecular self-assembled method. The biacid co-doped polyaniline as the conductance loss phase was anchored on the high aspect ratio ISNiCo2O4 surface, making the whole material have certain electrical conductivity and reduce the percolation value. The other components were acted as the dielectric loss phase to equilibrate impedance matching. Meanwhile, the design of interstice skeletal structure effectively decreased the density and equivalent permittivity. The electromagnetic parameters were availably controlled by the hierarchical structure, thus improving the absorbing ability of nanocomposites. The magnetic loss provided by ISNiCo2O4 was derived from the eddy current and natural resonance. We compared the absorption properties of different as-prepared unitary to ternary products, matrix additions and component contents, and found some meaningful conclusions. The maximum R-L value of ISNiCo2O4@BCDPANI/alpha-[SiW11Mn(H2O)O-39](6-) nanocomposites reached -52.4 dB with a thickness of only 1.6 mm, and the effective absorption bandwidth exceeding -10 dB was up to 6.5 GHz at only 1.9 mm. In contrast, as the conductance component content increased, the ternary nanocomposites showed better overall performance, but the thickness enlarged slightly, which the maximum absorption of -60.4 dB at 2.4 mm, an effective absorption bandwidth of 6.5 GHz at 2.9 mm, and bandwidth below -10 dB and -20 dB remarkably of 13.9 GHz and 11.1 GHz with the thickness range of 1.5-5 mm.

Automated summary

A highly effective electromagnetic wave absorber with great tunability of absorption strength and bandwidth was successfully prepared via a facile hydrothermal combined with supramolecular self-assembled method. The materials had certain electrical conductivity, reduced percolation value, equilibrated impedance matching, and effectively decreased density and equivalent permittivity. The magnetic loss provided by ISNiCo2O4 was derived from the eddy current and natural resonance, contributing to the absorbing ability of the nanocomposites.