Single-Atom Nanozyme-Like Lanthanum Moieties for High-Performance Electromagnetic Energy Absorption

Single-atom (SA) nanozymes have unprecedented physicochemical performance due to their integrated merits of both atomically dispersed metal atoms and bio-enzymes. However, the structure-function relationship between the SA nanozyme-like structure and its dielectric performance is still unclear. Furthermore, controllable synthesis of SA nanozyme-like structures remains challenging due to their unique five-coordinated configurations. Here, a dicyandiamide-mediated pyrolysis strategy is proposed to anchor five nitrogen-coordinated lanthanum (La)-N5 moieties on interconnected N-doped graphene nanocages (La-N5/ING). Theoretical predictions indicate that the spatially coordinated La-N5 moieties exhibit significantly enhanced conduction loss and polarization loss compared to La-N4 moieties, as evidenced by the experimental results. Moreover, the polydimethylsiloxane-coated chemically cross-linked film constructed by the La-N5/ING and aramid nanofibers has outstanding electromagnetic wave (EMW) absorption performance with an effective absorption bandwidth (EAB10) of 6.24 GHz at a thickness of merely 2.0 mm, outperforming those of most reported carbon-based films. Importantly, the film also has excellent flexibility, hydrophobicity, mechanical strength, and structural stability, ensuring its application potential in practical environments. These findings provide crucial insights into the microscopic environment of SA on the dielectric properties of their host materials, and a critical method for the preparation of multifunctional films with spatial coordinated SA. A facile strategy is proposed to anchor single-atom nanozyme-like lanthanum moieties on graphene nanocages, showing significantly enhanced dielectric loss performance due to unique five-coordinated configurations. The nanocages-based multifunctional film is fabricated and has outstanding electromagnetic wave absorption performance, outperforming most reported carbon-based films. This work provides crucial insights into the spatially coordinated environment of metal single-atom on the dielectric property. image