Hierarchical Magnetic Network Constructed by CoFe Nanoparticles Suspended Within “Tubes on Rods” Matrix Toward Enhanced Microwave Absorption

Abstract

Hierarchical magnetic-dielectric composites are promising functional materials with prospective applications in microwave absorption (MA) field. Herein, a three-dimension hierarchical “nanotubes on microrods,” core–shell magnetic metal–carbon composite is rationally constructed for the first time via a fast metal–organic frameworks-based ligand exchange strategy followed by a carbonization treatment with melamine. Abundant magnetic CoFe nanoparticles are embedded within one-dimensional graphitized carbon/carbon nanotubes supported on micro-scale Mo2N rod (Mo2N@CoFe@C/CNT), constructing a special multi-dimension hierarchical MA material. Ligand exchange reaction is found to determine the formation of hierarchical magnetic-dielectric composite, which is assembled by dielectric Mo2N as core and spatially dispersed CoFe nanoparticles within C/CNTs as shell. Mo2N@CoFe@C/CNT composites exhibit superior MA performance with maximum reflection loss of − 53.5 dB at 2 mm thickness and show a broad effective absorption bandwidth of 5.0 GHz. The Mo2N@CoFe@C/CNT composites hold the following advantages: (1) hierarchical core–shell structure offers plentiful of heterojunction interfaces and triggers interfacial polarization, (2) unique electronic migration/hop paths in the graphitized C/CNTs and Mo2N rod facilitate conductive loss, (3) highly dispersed magnetic CoFe nanoparticles within “tubes on rods” matrix build multi-scale magnetic coupling network and reinforce magnetic response capability, confirmed by the off-axis electron holography.

Flexible and Waterproof 2D/1D/0D Construction of MXene-Based Nanocomposites for Electromagnetic Wave Absorption, EMI Shielding, and Photothermal Conversion

“…Thus, combining magnetic nanoparticles with MXene can achieve enhanced electromagnetic dissipation materials, such as MXene/hollow Fe 3 O 4 [25], TiO 2 /Ti 3 C 2 T x /Fe 3 O 4 [26], MXene/Ni chain hybrid [27], Ti 3 C 2 T x @NiCo 2 O 4 [28]. The 0D magnetic nanoparticles decorated 1D CNTs can be derived from the metal-organic frameworks (MOFs) due to their tunable composition and microstructure [29][30][31]. In addition, substantial development of electromagnetic wave absorption and EMI shielding was achieved for MXene-based composites with a novel structure.…”

3D Seed-Germination-Like MXene with In Situ Growing CNTs/Ni Heterojunction for Enhanced Microwave Absorption via Polarization and Magnetization

“…It is widely accepted that a reasonable electromagnetic recombination method plays a key factor in the final MA performance [33]. Liu et al used simple blending method to compound MXene and Ni chain [31].…”

Composition Optimization and Microstructure Design in MOFs-Derived Magnetic Carbon-Based Microwave Absorbers: A Review

“…Of note is that Xu et al deposited ZIF-67 nanocrystals on MoO 3 nanorods and then converted the mixture into MoO 3 @Co-Fe PBAs through fast ligand exchange, and finally, a quadruple composite of Mo 2 N@CoFe@C/CNT could be generated by pyrolyzing MoO 3 @Co-Fe PBAs in the presence of melamine (Fig. 5 a) [ 105 ]. In this composite, abundant magnetic CoFe nanoparticles were encapsulated within one-dimensional graphitized carbon/carbon nanotubes supported on Mo 2 N nanorods (Fig.…”

“…Copyright © 2021 The Royal Society of Chemistry the presence of melamine (Fig. 5a) [105]. In this composite, abundant magnetic CoFe nanoparticles were encapsulated within one-dimensional graphitized carbon/carbon nanotubes supported on Mo 2 N nanorods (Fig.…”