Multi-heterostructure composites of Fe3O4 coated Janus nanoparticles and MWCNTs with high microwave absorption

Microwave-absorbing materials with heterostructure represent a major challenge and opportunity in enabling strong microwave absorption over a wide bandwidth. Here, novel hydrophilic multi-heterostructure composites (Mag@J/MWCNT) were fabricated by combining nanostructured Fe 3 O 4 covered snowman-like Janus nanoparticles (Mag@J) with MWCNTs for enhanced microwave absorption. The good hydrophilicity and low reflection loss (RL) demonstrated the potential application of Mag@J as an effective microwave absorbent with environmentally friendly processibility. Further, the multi-heterostructure composites constructed by Mag@J (with 77.73 wt% Fe 3 O 4 ) and MWCNTs exhibited strong absorption intensity (RL = −38.98 dB), wide bandwidth (6.04–8.23 GHz), and low thickness (3.5 mm). The excellent microwave absorption properties were attributed to the strong dielectric loss, magnetic loss, and good impedance matching of different components in multi-heterostructure composites, as well as multiple reflection absorption of microwave in the hollow sphere of Janus particle. Therefore, this work provides important inspiration for multi-heterostructure composites to achieve potential applications as electromagnetic wave absorbing materials.