Carbon Encapsulated Core-Shell Structure Znfe2o4 Sphere Composites Coupled with Excellent Microwave Absorption and Corrosion Resistance

Microwave absorbing materials (MAMs) have been regarded as an efficient strategy to solve serious electromagnetic pollution problems. Current composite MAMs with core-shell structures are always assembled as a magnetic core and a dielectric shell, which inevitably leads to suppressed magnetic coupling and impedance mismatch. Herein, carbon shell encapsulated core-shell structure zinc ferrate (ZnFe2O4) sphere composites (CSZF@C) were fabricated by a hydrothermal method and subsequent carbonization process. The complex permittivity and complex permeability of CSZF@C can be effectively adjusted by varying the parameters of the outer carbon shell. Benefiting from the unique microstructure, the synergetic effect of conductive carbon shell and inner core-shell structure ZnFe2O4 (CSZF) not only satisfy the impedance matching, but also improve the electromagnetic energy loss. As a thickness of CSZF@C is only 2.94 mm, CSZF@C-1 obtained a strong reflection loss (RL) value of -53.5 dB, while the effective absorption bandwidth (EAB) can be as wide as 6.56 GHz. Meanwhile, due to the carbon encapsulation, the epoxy resin coating of CSZF@C-1 effectively improves the corrosion resistance of the metal substrate. This study provides new ideas for the design of efficient multifunctional nanocomposites feathered with excellent microwave absorption and corrosion resistance performance.