Strengthened electromagnetic absorption performance derived from synergistic effect of carbon nanotube hybrid with Co@C beads

Abstract

The composite structure of Co beads (200-300 nm) threaded by carbon nanotubes has been synthesized through a facile solvothermal method followed by a carbon reduction process. A carbon layer of ca. 5 nm was coated on the surface of Co beads to form a coreshell structure (CNTs/Co@C), in favor of the antioxidation of Co nanoparticles. The CNTs/Co@C hybrid showed a saturation magnetization (M s ) of 82.5 emu g −1 and a larger H c value of 258.8 Oe than bulk Co (ca. 10 Oe). Served as an EM wave absorption material, the epoxy resin composites consisting of 60 wt% and 40 wt% CNTs/Co@C hybrid exhibited effective EM absorption (RL < − 10 dB) over the frequency ranges of 1.5-15 and 1.6-20 GHz with the matching thicknesses of 1.0-7.5 and 1.0-10.0 mm, respectively. The superior EM absorption performances of CNTs/Co@C hybrid containing strong absorption, wide frequency range, thin thickness, and light weight are mainly attributed to the synergy of magnetic loss from Co beads and dielectric loss from carbon nanotubes, as well as remarkable impedance matching.

Ultra-light MXene aerogel/wood-derived porous carbon composites with wall-like “mortar/brick” structures for electromagnetic interference shielding

“…Such ultralight and efficient EMI shielding materials are expected to be widely used in the high-end EMI shielding fields of aerospace and national defence industry, etc. [45].…”

Hierarchical Carbon Fiber@MXene@MoS2 Core‐sheath Synergistic Microstructure for Tunable and Efficient Microwave Absorption

“…Generally, dielectric loss and magnetic loss are well‐known mechanisms for MA design, which are also the most important considerations of researchers in the MA‐related material selection. Till now, diverse materials with improved MA performance have been obtained, including ferroelectric ceramics, [ 23–25 ] polymers, [ 26–28 ] as well as carbonaceous materials. [ 29–31 ] Recently, a class of metal carbide and metal nitride materials (MXene) with 2D‐layered structure has joined the family of novel MA‐related materials due to its high specific surface area, good conductivity, and metal‐like properties.…”

An Easy Method of Synthesis CoxOy@C Composite with Enhanced Microwave Absorption Performance

“…The corresponding fs value is 4.9 GHz. For comparison, the EM performance of Co or C containing hybrids are listed in Table 1, demonstrating that the Co/Co3O4@C hybrids shows improvement of EM absorption ability [32][33][34][35][36][37][38][39]. It should be noted that EM absorption performance is always determined by the impedance matching and EM attenuation ability.…”