Hierarchical Magnetic Network Constructed by CoFe Nanoparticles Suspended With in "Tubes on Rods" Matrix Toward Enhanced Microwave Absorption

• 作者: Chunyang Xu Lei Wang Xiao Li Xiang Qian Zhengchen Wu Wenbin You Ke Pei Gang Qin Qingwen Zeng Ziqi Yang Chen Jin Renchao Che
• 来源期刊: 纳微快报（英文）
• 年，卷（期）: 2021,（3）
• 页码范围: 80-94
• 页数: 15页
• 语种: 英文

摘要

Hierarchical magnetic-dielectric composites are prom-ising 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 ration-ally 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 spe-cial 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 conduc-tive 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.