Defect Engineering Activates Schottky Heterointerfaces of Graphene/CoSe2 Composites with Ultrathin and Lightweight Design Strategies to Boost Electromagnetic Wave Absorption

To tackle the increasingly complex electromagnetic (EM) pollution environment, the application-oriented electromagnetic wave (EMW) absorption materials with ultra-thin, light weight and strong tolerance to harsh environment are urgently explored. Although graphene aerogel-based lightweight EMW absorbers have been developed, thinner thickness and more effective polarization loss strategies are still essential. Based on the theory of EMW transmission, this work innovatively proposes a high attenuation design strategy for obtaining ultra-thin EMW absorption materials, cobalt selenide (CoSe2) is determined as animportant part of ultra-thin absorbers. In order to obtain a dielectric parameter range that satisfies the ultra-thin absorption characteristics and improve the lightweight properties of EMW absorption materials, a composite of CoSe2 modified N-doped reduced graphene oxide (N-RGO/CoSe2) is designed. Meanwhile, the controllable introduction of defect engineering into RGO can activate Schottky heterointerfaces of composites to generate a strong interfacial polarization effect, achieving ultra-thin characteristics while significantly improving the EM loss capability. In addition, infrared thermal images and anti-icing experiments show that the composite has good corrosion resistance, infrared stealth, and thermal insulation properties. Therefore, this work provides an effective strategy for obtaining thin-thickness, light-weight, and high-performance EMW absorption materials, embodying the advantages of N-RGO/CoSe2 composites in practical applications.