Preparation and characterization of branch-like heteroatoms-doped Ni@C nanofibers for high-performance microwave absorption with thin thickness

Abstract

Magnetic Ni@C nanofibers with branch-like multiwall carbon nanotubes (MWCNTs) were prepared through a two-step strategy of electrospinning and following in situ pyrolysis to explore the electromagnetic microwave absorption (MA) performance. The morphology and chemical composition were controlled by mass ratio of nickel (II) acetylacetone (Ni(acac)2) and poly (phthalazinone ether nitrile ketone) (PPENK) resin. 3D structure with branch-like morphology extends the transmission path of microwave and reduces the thickness effectively. The heteroatoms-doped Ni@C nanofibers reach the optimal reflection loss value of −53.2 dB at 14.3 GHz and effective absorption bandwidth of 5.6 GHz from 12.4 to 18.0 GHz with rather thin thickness of 1.5 mm. The MA mechanisms are discussed in detail and the multi-component nanofibers of magnetic Ni particles and nonmagnetic carbon have achieved synergistic effect of dielectric and magnetic loss. This work explores the relevancy of morphology and composition on microwave absorption performance, revealing a potential application for excellent microwave absorber with low filler ratio and thinner matching thickness.