文献类型：期刊文献

英文题名：Oxygen-vacancy-rich Fe3O4/carbon nanosheets enabling high-attenuation and broadband microwave absorption through the integration of interfacial polarization and charge-separation polarization

作者：Su, Zhe[1];Zhang, Wanyu[1];Lu, Jiawei[1];Tian, Liying[1];Yi, Shan[1];Zhang, Yayun[1];Zhou, Shenghu[1];Niu, Bo[1];Long, Donghui[1]

机构：[1]East China Univ Sci & Technol, Sch Chem Engn, Shanghai Key Lab Multiphase Mat Chem Engn, Shanghai 200237, Peoples R China

年份：2022

卷号：10

期号：15

起止页码：8479

外文期刊名：JOURNAL OF MATERIALS CHEMISTRY A

收录：;EI(收录号：20221511955534);WOS:【SCI-EXPANDED(收录号:WOS:000770041500001)】；

基金：This work was supported by the National Natural Science Foundation of China (No. 22078100, No. 21878091, No. 22008073, and No. 52102098) and Fundamental Research Funds for the Central Universities (No. 222201718002). The authors also acknowledge Prof. Tao Liu (East China University of Science and Technology, School of Chemical Engineering) for supporting rheological analysis.

语种：英文

外文关键词：Carbonization - Metals - Nanosheets - Polarization - Dielectric materials - Microwaves - Oxygen vacancies - Density functional theory - Nanocrystals - Synthesis (chemical)

摘要：Metal-oxide/carbon composites with remarkable dielectric-magnetic properties are promising as microwave absorption materials, but achieving high-attenuation and broadband microwave absorption properties still remains challenging. Herein, we develop a one-step carbonization of the ferric gluconate precursor to manufacture two-dimensional oxygen-vacancy-rich Fe3O4/carbon nanosheets (Fe3O4/C) for high-attenuation microwave absorption. The key to the synthesis is employing the Fe3+-gluconate complex as the precursor, which has the ability to release small molecules within the viscosity foaming window to spontaneously obtain a 3D self-foamed material. Followed by high-temperature annealing, the as-obtained Fe3O4/C hybrid composite features large lamellar (>20 mu m) carbon nanosheets with abundant yolk-shell heterostructures and highly dispersed and high-loaded (similar to 44%) oxygen-vacancy-rich Fe3O4 nanocrystals. The unique 2D structure could facilitate multiple scattering absorption and interconnect into a 3D conductivity-loss network. Meanwhile, the abundant yolk-shell heterostructures could trigger extra interfacial polarization. And density functional theory calculation results demonstrate that oxygen vacancies endow magnetic Fe3O4 nanocrystals with charge-separation induced polarizations. Consequently, Fe3O4/C exhibit superior microwave absorption capability with an impressive reflection loss (RL) of -65.4 dB and an ultra-broad effective absorption bandwidth of 6.24 GHz. The spontaneous foaming strategy in this work could provide feasible technological approaches for the practical fabrication of microwave absorption materials.