Tuning the shell thickness of core-shell α-Fe2O3@SiO2 nanoparticles to promote microwave absorption

作者：Fu, Honghong; Guo, Yue; Yu, Jian; Shen, Zhen; Zhao, Jie^*; Xie, Yu; Ling, Yun; Ouyang, Sheng; Li, Shiqi; Zhang, Wei^*

来源：CHINESE CHEMICAL LETTERS, 2022, 33(2): 957-962.

DOI：10.1016/j.cclet.2021.07.027

• alpha-Fe2O3@SiO2
• Core-shell structure
• Microwave absorption
• Dielectric loss
• Interfacial polarization
• Conductivity loss

Various advanced microwave absorbing materials have been developed for reducing/avoiding the harm of microwave radiation. Among them, core-shell structural nanomaterials have been widely fabricated for microwave absorption. However, the "structure-performance" relationship between shell thickness and microwave absorption performance is rarely reported. In this paper, we first explored the "structure-performance" relationship between shell thickness and microwave absorption performance, based on the core-shell alpha-Fe2O3@SiO2 nanoparticles with a constant alpha-Fe2O3-core size and changeable SiO2-shell thickness. With increasing the SiO2-shell thickness, the microwave absorption ability first increased, then decreased. Under a proper SiO2-shell thickness of 35 nm, alpha-Fe2O3@SiO2 sample achieved the strongest microwave absorbing ability with a reflection loss minimum value of -4.3 dB, better than that of pure alpha-Fe2O3 (-3.8 dB). This enhanced microwave absorption performance was mainly derived from the dielectric loss. Although the absolute value of the reflection loss was relatively low (-4.3 dB), this study shed an important reference on designing next-generation advanced iron oxide-based materials for microwave absorption.

• 单位
  南昌航空大学; 南京大学; 郑州大学; 北京航空航天大学