Multi-dimensional Ni@C-CoNi composites with strong magnetic interaction toward superior microwave absorption

Dielectric-magnetic integrated absorbers have attracted arousing attention in microwave absorption,however,it still remains a great challenge to simultaneously achieve superior dielectric polarization and strong magnetic loss.Herein,we propose a multi-scale structure optimization strategy to anchor CoNiMOFs derived OD CoNi alloy onto 1 D core-shell Ni@C surface.By decorating with the poly-dopamine layer,the connection between 1 D NiO and CoNi-MOFs precursors was greatly improved via the electrostatic interaction.Benefiting from the overlapping conductive networks,enhanced interfacial polarization among the multi-dimensional heterogeneous interfaces and strong magnetic interaction,the fabricated multi-dimensional Ni@C-CoNi composites exhibit outstanding microwave absorption.Typically,the optimal reflection loss is as high as-51.4 dB at 1.9 mm,and the effective absorption bandwidth achieves 4.6 GHz with a thickness of only 1.3 mm.This multi-scale structure optimization strategy inspires us with an efficient method to fabricate ideal microwave absorbers and the obtained multi-dimensional composites can be used as promising candidates in electromagnetic radiation protection.