Robust silica and carbon bilayers decorating spherical FeCo alloys for high-performance anti-corrosion microwave absorption

The requirements of microwave absorbers are increasing year by year. However, a great challenge is the coupling of high microwave absorption and corrosion-resistant. To solve these problems, herein, a robust FeCo@SiO2 @C gradient composite was designed through the Stober method and chemical vapor deposition (CVD) technique to achieve efficient microwave absorption and anti-corrosion. These silica/carbon bilayers possess a rich interface structure, reduce the dielectric constant, and optimize impedance matching, which favors to address efficient microwave absorbing performance with a minimum reflection loss of - 43.93 dB at 7.89 GHz in case of the 4 mm matching thickness. After decorating the silica/carbon bilayers on the FeCo surface, the excellent corrosion shielding protection for the inner FeCo alloy was well addressed. And the polarization resistance increased from 1.21 x 105 a center dot cm2 to 4.65 x 105 a center dot cm2. The corrosion current de-creased from 8.623 x 10-6 A/cm2 to 1.357 x 10-6 A/cm2. This high curie temperature magnetic/silica/carbon novel hybrid reduces electromagnetic pollution and opens up a new opportunity to construct an advanced microwave absorber with anti-corrosion function. (c) 2022 Elsevier B.V. All rights reserved.