Coupled multiple heterogeneous interfaces lychee-like FeSiAl@C@SiO2@BTA for self-healing corrosion protection and enhanced microwave absorption

Abstract

Corrosion-resistant ferromagnetic absorbers (FMAs) with self-healing properties are crucial for enhancing their durability under harsh conditions. Herein, we fabricated lychee-like FeSiAl (FSA)@C@SiO2@1H-Benzotriazol (BTA) coupled with multiple heterogeneous interfaces by coating FSA with a C@SiO2@BTA layer using sol-gel, thermal reduction, and molecular encapsulation techniques. The FSA@C@SiO2@BTA showed superior microwave absorption (MA) performance than FSA, with a widest absorption bandwidth of 10.44 GHz at 1.98 mm and a maximum reflection loss of −57.81 dB at 2.98 mm. The enhanced MA performance was due to the better impedance matching and the synergistic effects of interfacial and dipole polarization induced by the C@SiO2@BTA layer. Moreover, the FSA@C@SiO2@BTA exhibited a remarkable corrosion resistance, with a corrosion rate of 3.28 × 10−10 m/s, which was two orders of magnitude lower than that of FSA, and a corrosion protection efficiency of 99.0 %. The epoxy resin coating containing FSA@C@SiO2@BTA also demonstrated a self-healing ability within 5 min after being damaged mechanically. This study presents a novel model that integrates MA, corrosion resistance, and self-healing, heralding new avenues for developing corrosion-resistant FMAs in marine applications.