文献类型：期刊文献

英文题名：Ultrafine Vacancy-Rich Nb2O5 Semiconductors Confined in Carbon Nanosheets Boost Dielectric Polarization for High-Attenuation Microwave Absorption

作者：Su, Zhe[1];Yi, Shan[1];Zhang, Wanyu[1];Xu, Xiaxi[1];Zhang, Yayun[1];Zhou, Shenghu[1];Niu, Bo[1];Long, Donghui[1,2]

机构：[1]East China Univ Sci & Technol, Sch Chem Engn, Shanghai Key Lab Multiphase Mat Chem Engn, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Key Lab Specially Funct Mat & Related Technol, Minist Educ, Shanghai 200237, Peoples R China

年份：2023

卷号：15

期号：1

外文期刊名：NANO-MICRO LETTERS

收录：;EI(收录号：20233014427390);WOS:【SCI-EXPANDED(收录号:WOS:001027439900001)】；

基金：AcknowledgementsThis work was supported by National Natural Science Foundation of China (No. 22078100, No. 52102098, and No. 22008073) and Fundamental Research Funds for the Central Universities (No. 222201718002). The authors would like to thank Shiyanjia Lab (www.shiyanjia.com) for the XPS analysis.

语种：英文

外文关键词：Electromagnetic wave absorption; Nb2O5 semiconductor; Dielectric polarization loss; Oxygen vacancy; Nb2O5- carbon hetero-interface

摘要：The integration of nano-semiconductors into electromagnetic wave absorption materials is a highly desirable strategy for intensifying dielectric polarization loss; achieving high-attenuation microwave absorption and realizing in-depth comprehension of dielectric loss mechanisms remain challenges. Herein, ultrafine oxygen vacancy-rich Nb2O5 semiconductors are confined in carbon nanosheets (ov-Nb2O5/CNS) to boost dielectric polarization and achieve high attenuation. The polarization relaxation, electromagnetic response, and impedance matching of the ov-Nb2O5/CNS are significantly facilitated by the Nb2O5 semiconductors with rich oxygen vacancies, which consequently realizes an extremely high attenuation performance of - 80.8 dB (> 99.999999% wave absorption) at 2.76 mm. As a dielectric polarization center, abundant Nb2O5-carbon heterointerfaces can intensify interfacial polarization loss to strengthen dielectric polarization, and the presence of oxygen vacancies endows Nb2O5 semiconductors with abundant charge separation sites to reinforce electric dipole polarization. Moreover, the three-dimensional reconstruction of the absorber using microcomputer tomography technology provides insight into the intensification of the unique lamellar morphology regarding multiple reflection and scattering dissipation characteristics. Additionally, ov-Nb2O5/CNS demonstrates excellent application potential by curing into a microwave-absorbing, machinable, and heat-dissipating plate. This work provides insight into the dielectric polarization loss mechanisms of nano-semiconductor/carbon composites and inspires the design of high-performance microwave absorption materials.