Size regulated N-doped carbon encapsulated NiFe alloys/Ni phosphide composites derived from bimetallic Prussian blue analogues for effective microwave absorption

Abstract

Prussian blue analogues (PBAs) derivatives have emerged as microwave absorbing materials to address electromagnetic pollution in recent years. In this work, bimetallic NiFe-PBA derived multi-interface N-doped carbon (NC) encapsulated NiFe alloys/Ni phosphide composites (NFPC) were prepared by thermal treatment and phosphating process. The PBAs samples with different chemical compositions and particle sizes were synthesized by manipulating the proportions of raw materials. The particle sizes of PBAs significantly impact the morphology, phosphating degree and electromagnetic properties of the NFPC composites. The results indicated that the NFPC composites exhibit excellent microwave absorption performance, with a minimum reflection loss of −41.4 dB at 1.36 mm and the effective absorption bandwidth of 4.4 GHz at 1.34 mm. The corresponding microwave attenuation mechanisms of NFPC composites were further investigated. This study not only presents a comprehensive investigation into the controlled growth of PBAs, but also provides innovative design strategies and valuable insights on utilizing multiple interfacial magnetic alloys/phosphides@NC composites as efficient microwave absorbing materials.