Interface engineering and impedance matching strategy to develop core@shell urchin-like NiO/Ni@carbon nanotubes nanocomposites for microwave absorption

It is well recognized that interfacial effect and/or impedance matching play a great impact on microwave absorption. Herein, we proposed a facile strategy to take full advantage of interface engineering and impedance matching for boosting microwave absorption performance (MAPs). Three-dimensional (3D) hierarchical urchin-like core@shell structured NiO/Ni@CNTs multicomponent nanocomposites (MCNCs) were elaborately constructed and produced in high efficiency through a facile continuous chemical bath deposition, thermal treatment, and catalytic chemical vapor decomposition process. By controlling the pyrolysis time, the NiO/Ni@CNTs urchin-like MCNCs with different lengths and aggregation degrees of CNTs could be selectively synthesized. The obtained results revealed that the enhanced CNT contents provided abundant interfaces and effectively aggrandized their interfacial effects, which resulted in improved polarization loss, conductivity loss, and comprehensive MAPs. Impressively, the interfaces and impedance matching in the designed NiO/Ni@CNTs urchin-like MCNCs could be optimized by regulating the pyrolysis temperature, which further improved the comprehensive MAPs. And the designed NiO/Ni@CNTs urchin-like MCNCs could simultaneously display strong absorption capabilities, broad absorption bandwidths, and thin matching thicknesses. Therefore, our findings not only provided a simple and universal approach to produce core@shell structured magnetic carbon-based urchin-like MCNCs but also presented an interface engineering and impedance matching strategy to develop the tunable, strong absorption, broadband, lightweight high-efficiency microwave absorbers.