An environmentally friendly solvent-free strategy for synthesis of velutipes-shaped Ni@CNTs-x composites as high-performance electromagnetic wave (EMW) absorbers by combining Ni particles with carbon nanotubes (Ni@CNTs) through in situ pyrolysis of a mixture of nickel nitrate and melamine is proposed. The CNTs contained several microporous structures, thereby facilitating a reduction in density and an enhancement of the EMW absorption. The EMW absorption performance first increased then decreased with increasing Ni content. The effective absorption bandwidth (RL < −10 dB) of the synthesized Ni@CNTs-x was up to 5.45 GHz for a thickness of 1.79 mm, while the minimum reflection loss (RL_min) was −60.56 dB at 17.32 GHz for a thickness of 1.582 mm and 20 wt.% loading. Overall, the results of this study indicate that this facile environmentally friendly method is effective to prepare excellent, thin, lightweight EMW absorbers with wide absorption bandwidth and high absorption efficiency.

通过原位热解镍混合物将镍颗粒与碳纳米管（Ni @ CNTs）结合起来，合成出天鹅绒状Ni @ CNTs- x复合材料作为高性能电磁波（EMW）吸收剂的无溶剂环保策略提出了硝酸盐和三聚氰胺。CNT包含几个微孔结构，从而促进密度的降低和EMW吸收的增强。随着Ni含量的增加，EMW的吸收性能首先增加，然后下降。厚度为1.79 mm的合成Ni @ CNTs- x的有效吸收带宽（RL <-10 dB）高达5.45 GHz，而最小反射损耗（RL _min对于1.582 mm的厚度和20 wt。％的负载，在17.32 GHz时为-60.56 dB。总体而言，这项研究的结果表明，这种简便的环保方法可有效地制备具有宽吸收带宽和高吸收效率的优质，薄，轻的EMW吸收剂。