Construction of SnO2/Co3Sn2@C and SnO2/Co3Sn2@Air@C hierarchical heterostructures for efficient electromagnetic wave absorption

The multi-heterogeneous components and structural design are efficient strategies for enhancing the absorption of electromagnetic wave. In order to achieve stronger interface polarization and better impedance matching, two types of hierarchical heterostructures of SnO2/Co3Sn2@C and SnO2/Co3Sn2@Air@C were fabricated through an environment friendly approach and their electromagnetic absorption performances were investigated. It was demonstrated that both products are composed of binary core SnO2/Co3Sn2 and porous carbon shell. Particularly, one core is closely stacked in the form of numerous nanoparticles, while the other core assembles into a ball and an internal cavity exists between the core and shell. Benefitting from the synergistic effects of heterogeneous dielectric materials, abundant interfaces polarization and special porous structure, SnO2/Co3Sn2@C hybrid shows excellent microwave absorption performance with RL value of -56.2 dB at 6.8 GHz and minimum effective absorption thickness of 1.7 mm corresponding to the RL value of -46.8 dB. In addition to strong absorption, SnO2/Co3Sn2@Air@C composite possesses superior broadband microwave absorption characteristics with an ultrabroad bandwidth up to 6.1 GHz (11.0-17.1 GHz) due to impedance matching mediators of the pore/void. This study opens up a fresh exploration of designing novel electromagnetic wave absorbing materials.