Wang Fengyuan, Liu Yonglei, Feng Rida, Wang Xuan, Han Xijiang, Du Yunchen
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China.
Small. 2023 Nov;19(48):e2303597. doi: 10.1002/smll.202303597. Epub 2023 Aug 1.
3D carbon foams have demonstrated their superiority in the field of microwave absorption recently, but the preparation processes of traditional graphene foams are complicated, while some novel carbon foams usually suffer from inadequate dielectric property. Herein, a simple "win-win" strategy is demonstrated to synchronously realize the construction of 3D Co/C foam and its surface decoration with carbon microspheres. Therein, the host Co/C foams and guest carbon microspheres interact with each other, resulting in the improvement of the dispersity of carbon microspheres and Co nanoparticles. The bilaterally synergistic effect can effectively enhance the interfacial polarization and conductive loss of these obtained samples. Electromagnetic analysis reveals that the optimized sample with moderate carbon microsphere content (about 33.5 wt%) displays a widened maximum effective absorption bandwidth of 5.2 GHz and a consolidated reflection loss intensity of -67.6 dB. Besides, the microwave absorption enhancement mechanisms are investigated and discussed in detail. It is believed that this work provides valuable ideas for the development of 3D-foam-based microwave absorbing materials for practical applications.
3D碳泡沫材料最近在微波吸收领域展现出了其优越性，但传统石墨烯泡沫的制备过程复杂，而一些新型碳泡沫通常存在介电性能不足的问题。在此，展示了一种简单的“双赢”策略，可同步实现3D Co/C泡沫的构建及其表面碳微球的修饰。其中，主体Co/C泡沫和客体碳微球相互作用，导致碳微球和Co纳米颗粒的分散性得到改善。这种双向协同效应能够有效增强所得样品的界面极化和传导损耗。电磁分析表明，具有适度碳微球含量（约33.5 wt%）的优化样品展现出5.2 GHz的加宽最大有效吸收带宽和-67.6 dB的巩固反射损耗强度。此外，还对微波吸收增强机制进行了详细研究和讨论。相信这项工作为开发用于实际应用的基于3D泡沫的微波吸收材料提供了有价值的思路。
