Flexible Film Constructed by Asymmetrically‐Coordinated La₁N₄Cl₁ Moieties on Interconnected Nitrogen‐Doped Graphene Nanocages for High‐Efficiency Electromagnetic Wave Absorption

Abstract The microenvironments of metal single‐atoms (SAs) have important effects on their physicochemical properties. However, the understanding of the relationship between the coordination configuration of SAs and their properties is insufficient. Here, a sacrificing template strategy is developed to anchor La‐SAs on interconnected graphene nanocages (La‐N‐Cl/GNC), where La‐SAs are located above the graphene plane and one La atom coordinated with four N atoms in the graphene plane and with one Cl atom along the axial direction. Theoretical calculations demonstrated that asymmetrically La‐SAs are more conducive to breaking local charge symmetry. Consequently, additional electrical dipoles along the axial direction are generated, leading to unprecedented dipolar polarization loss and strong electromagnetic wave absorption properties. Moreover, the film constructed by asymmetrically‐coordinated La‐N‐Cl/GNC with a mass density of 0.084 g cm⁻³ exhibits superior flexibility, excellent mechanical strength, and moderate thermal insulation properties, guaranteeing its practical applications in harsh environments. These findings not only shed light on the relationships between asymmetrically coordinated SAs and their dielectric properties at the atomic level but also provide an efficient method for preparing multifunctional films.