Liang Hongsheng, Hui Shengchong, Zhang Limin, Tao Kai, Chen Qiang, Lu Wei, Wu Hongjing
Shanghai Key Laboratory of D&A for Metal-Functional Materials, School of Materials Science & Engineering, Tongji University, Shanghai, 201804, P. R. China.
MOE Key Laboratory of Material Physics and Chemistry under Extraordinary, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an, 710072, P. R. China.
Small. 2025 Jan;21(3):e2408396. doi: 10.1002/smll.202408396. Epub 2024 Nov 27.
Dual atoms (DAs), characterized by flexible structural tunability and high atomic utilization, hold significant promise for atom-level coordination engineering. However, the rational design with high-density heterogeneous DAs pairs to promote electromagnetic wave (EMW) absorption performance remains a challenge. In this study, high-density Ni─Cu pairs coupled DAs absorbers are precisely constructed on a nitrogen-rich carbon substrate, achieving an impressive metal loading amount of 4.74 wt.%, enabling a huge enhancement of the effective absorption bandwidth (EAB) of EMW from 0 to 7.8 GHz. Furthermore, the minimum reflection loss (RL) is -70.96 dB at a matching thickness of 3.60 mm, corresponding to an absorption of >99.99% of the incident energy. Both experimental results and theoretical calculations indicate that the synergistic effect of coupled Ni─Cu pairs DAs sites results in the transfer of electron-rich sites from the initial N sites to the Cu sites, which induces a strong asymmetric polarization loss by this redistribution of local charge and significantly improves the EMW absorption performance. This work not only provides a strategy for the preparation of high-density DA pairs but also demonstrates the role of coupled DA pairs in precisely tuning coordination symmetry at the atomic level.
双原子（DAs）具有结构可调性灵活和原子利用率高的特点，在原子级配位工程方面具有巨大潜力。然而，合理设计高密度异质双原子对以提升电磁波（EMW）吸收性能仍是一项挑战。在本研究中，在富氮碳基底上精确构建了高密度镍-铜对耦合双原子吸收体，实现了高达4.74 wt.% 的可观金属负载量，使EMW的有效吸收带宽（EAB）从0到7.8 GHz得到极大增强。此外，在匹配厚度为3.60 mm时，最小反射损耗（RL）为-70.96 dB，对应于对入射能量 >99.99% 的吸收。实验结果和理论计算均表明，镍-铜对耦合双原子位点的协同效应导致富电子位点从初始的氮位点转移至铜位点，通过这种局部电荷的重新分布引发强烈的不对称极化损耗，显著提高了EMW吸收性能。这项工作不仅为制备高密度双原子对提供了一种策略，还展示了耦合双原子对在原子水平精确调控配位对称性方面的作用。
