High-Density Dual Atoms Pairs Coupling for Efficient Electromagnetic Wave Absorbers.

Abstract

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 4.74wt.%, enabling a huge enhancement of the effective absorption bandwidth (EAB) of EMW from 0 to 7.8GHz. Furthermore, the minimum reflection loss (RLmin) is -70.96dB at a matching thickness of 3.60mm, 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.