Fe0.64Ni0.36@C and Mo2C@C heterostructures embedded in N−doped carbons as microwave absorbers

Multi−component absorbers can improve microwave absorption performance by incorporating multiple loss mechanisms. However, many multi−component absorbers containing magnetic metal-based nanomaterials are unstable, owing to aggregation and oxidation of metal nanomaterials. In this work, (Fe0.64Ni0.36 @C/Mo2C@C)@N − C composites were prepared by mixing nickel molybdate, potassium ferricyanide, and dopamine to form a precursor which was subsequently carbonized. The Fe0.64Ni0.36 and Mo2C nanoparticles in the composites were stabilized by a thin graphitic carbon coating and uniformly dispersed throughout the N-C matrix. This unique structure provided abundant interfaces for microwave absorption, whilst also effectively inhibiting the aggregation and oxidation of the metal-containing phases. One of the prepared composites, (Fe0.64Ni0.36 @C/Mo2C@C)@N − C− 3, possessed excellent microwave absorption properties, evidenced by a wide effective absorption bandwidth (EAB) of 5.7 GHz (11.9 −17.6 GHz) at 2.0 mm thickness, and the minimum reflection loss value (RLmin) of − 37.5 dB at 11.92 GHz and 2.5 mm thickness (at a filling amount of 16.7%).