Microstructure Optimization Strategy of Znin2s4/Rgo Composites Toward Enhanced and Tunable Electromagnetic Wave Absorption Properties

Abstract

Although microstructure optimization is an effective strategy to improve and regulate electromagnetic wave (EMW) absorption property, it remains a challenging task to prepare microwave absorbents with enhanced EMW absorbing performance and tuned absorption band by a simple method. Herein, ZnIn2S4/rGO composites with flower-like and cloud-like morphologies were fabricated by a convenient hydrothermal method. The ZnIn2S4/rGO composites with different morphologies realize efficient microwave absorption and tunable absorption bands, covering a wide frequency range. The flower-like structure has an optimal reflection loss (RL) of up to -49.2 dB with a maximum effective absorption bandwidth (EAB) of 5.7 GHz, and its main absorption peaks are concentrated in the C and Ku bands. The minimal RL of the cloud-like structure can reach -36.3 dB, and the absorption peak shifts to the junction of X and Ku bands. The distinguished microwave absorption capacity originates from the uniquely optimized microstructure, the complementary effect of ZnIn2S4 and rGO in dielectric constant, and synergy of various loss mechanisms, such as interfacial polarization, dipole polarization, conductive loss and multiple reflection. This work proposes a guide for the structural optimization of an ideal microwave absorber to achieve efficient and tunable EMW absorption performance.

Keywords: ZnIn2S4, Reduced graphene oxide, morphologies, microwave absorption；tunable absorption band