Synthesis of 3D cruciform CuZn@N-doped carbon with enhanced heterogeneous interfaces for high-efficiency electromagnetic wave absorption in C, X and Ku bands

Electromagnetic pollution makes high-efficiency microwave absorption increasingly significant. Preparation of non-magnetic bimetallic MOFs derivatives is an effective strategy to break the mindset of magnetic derivatives designing electromagnetic wave absorption materials. Herein, 3D cruciform CuZn MOF was creatively synthesized by in-situ growth and further carbonization to form CuZn@N-doped carbon (CuZn@NC). Benefited from the enhanced coupling interaction and interfacial polarization, 3D cruciform CuZn@NC possesses multiple ultra-strong absorption peaks exceeding -50 dB in C, X and Ku band. The effective absorption bandwidths (EABs) of CuZn@NC reach 6.4 GHz at 2.38 mm and 4 GHz at 3.3 mm, which realizes the complete coverage of Ku and X band, respectively. In addition, all the reduction of the radar cross section (RCS) of CuZn@NC-900-25 exceeds -18 dB m(2) in the entire simulation detection angle range (-90 degrees < theta < 90 degrees), which means that the samples can effectively attenuate more than 98 % radar monitoring signal in any directions, showing superior practical application value. The 3D cruciform CuZn@NC exhibits the characteristics of strong reflection loss, low thickness, ultra-wide EAB, non-toxic and pollution-free. This work demonstrates that non-magnetic composites also exist excellent electromagnetic wave attenuation ability through constructing reasonable hierarchical constituent and heterogeneous interfaces.