Urchins CuCo₂S₄/Carbon composites with abundant defects and hetero-interfaces for optimized impedance matching and broadened effective band width

This work adopts a composite strategy combining “large anisotropic structure” and “strong dielectric material”, which is a pioneer work reported on urchins CuCo₂S₄/C absorber. An environmentally friendly (eco-friendly) CuCo₂S₄/C composites were prepared through a facile route including an ion exchange method and a simple physical grinding process. The resultant CuCo₂S₄/C composites exhibit an urchins-like morphology with carbon nanoparticles anchored randomly on the tentacles of the urchins. The urchins CuCo₂S₄/C composites display an optimal reflection loss value of −44.2 dB at the thickness of 2.2 mm, and the effective bandwidth with RL < −10 dB reaches 7.12 GHz at a thickness of 2.4 mm. The outstanding electromagnetic (EM) wave absorption performance is mainly benefited from the synergistic effects between the anisotropic structure of CuCo₂S₄ and conductive carbon particles. By adjusting the component ratio during the grinding process, an optimized combination of conduction loss and polarization loss can be achieved, and the impedance matching level can be regularly controlled and improved while increasing the effective absorption bandwidth. These results indicate that the sea urchin CuCo₂S₄/C composite material designed in this work can serve as an ideal candidate for high-performance electromagnetic wave absorption and has certain reference significance for the development of more sulfide semiconductor based absorbing materials.