Atomization‐Induced High Intrinsic Activity of a Biocompatible MgAl‐LDH Supported Ru Single‐Atom Nanozyme for Efficient Radicals Scavenging

Abstract Developing efficient nanozymes to mimic natural enzymes for scavenging reactive radicals remains a significant challenge owing to the insufficient activity of conventional nanozymes. Herein, we report a novel Ru single‐atom nanozyme (SAE), featuring atomically dispersed Ru atoms on a biocompatible MgAl‐layered double hydroxide (Ru 1 /LDH). The prepared Ru 1 /LDH SAE shows high intrinsic peroxidase (POD)‐like catalytic activity, which outperforms the Ru nanoclusters (NCs) nanozyme by a factor of 20 and surpasses most SAEs. The density functional theory calculations reveal that the high intrinsic POD‐like activity of Ru 1 /LDH can be attributed to a heterolytic path of H 2 O 2 dissociation on the single Ru sites, which requires lower free energy (0.43 eV) compared to the homolytic path dissociation on Ru NC (0.63 eV). In addition, the Ru 1 /LDH SAE shows excellent multiple free radicals scavenging ability, including superoxide anion radical (O 2 ⋅ − ), hydroxyl radical (⋅OH), nitric oxide radical (NO⋅) and 2, 2‐diphenyl‐1‐picrylhydrazyl radical (DPPH⋅). Given the advantages of Ru 1 /LDH with high enzymatic activities, biosafety, and ease to scale up, it paves the way for exploring SAEs in the practical biological immunity system.