Heterogeneous interface engineering of rod-like M−Mo−N (M = Co, Ni) bimetallic nitrides for efficient microwave absorption

M−Mo−N (M = Co, Ni) bimetallic nitrides, known for their distinctive mechanical, magnetic and electrical properties, hold significant potential as microwave absorption (MA) materials. However, it remains challenge to obtain high-performance microwave absorbers from these bimetallic nitrides. In this work, the rod-like MoO 2 /Co 2 Mo 3 N/Co 3 Mo 3 N/Ni 3 Mo 3 N (MoCoNi) composites consisting of connected nanoparticles are fabricated in situ. The plentiful interfaces between the connected nanoparticles and between the different components effectively enhance the interfacial polarization, the rod-like structure benefits to conduction loss, and crystal defects facilitate strong dipole polarization. Therefore, MoCoNi composites achieve outstanding absorption properties with the reflection loss of −55.69 dB at 8.08 GHz and the effective absorption bandwidth of 6.48 GHz (11.36–17.84 GHz) at 2.4 mm. The actual MA performance of MoCoNi composites is verified through radar cross section simulation. This study proposes a novel approach for the utilizing of M−Mo−N (M = Co, Ni) bimetallic nitrides in microwave absorptions.