Nickel Nanoparticles\nEncapsulated in N‑Doped\nCarbon Nanotubes for Microwave Absorption

Abstract

Transition\nmetal composites doped with heteroatomic nitrogen and\nhaving a hierarchical porous structure are considered to be an effective\nway to improve the electromagnetic wave absorption ability of carbon-based\nabsorbent materials. In this work, a mixture of melamine, glucose,\nand nickel nitrate was used as a precursor to synthesize a multi-interface\ncarbon nanotube network with tubular morphology by one-step catalytic\npyrolysis. The absorption mechanism was further discussed in detail.\nThe composite materials have a better complementary loss mechanism\nand good matching impedance capability by combining carbon and magnetic\nNi nanoparticles. Notably, 6.4Ni/CNTs-900 exhibits a strong reflection\nloss (RL) of −49.3 dB at 8.88 GHz with a low filling content\nof 15% and an effective bandwidth (EAB, RL ← 10 dB) of 2.96\nGHz. The excellent microwave absorption properties of these materials\ncan be attributed to the multiple scattering, interface polarization,\ndipole polarization, and conductivity loss induced by the unique structure\nof the multi-interface carbon nanotube network. This work provides\na method for managing electromagnetic radiation pollution, which has\ngreat potential for efficient microwave absorption.