Boosting the Photocatalytic Performance of Layered Double Hydroxides by In Situ Reactions with Metal Nanoclusters

ABSTRACT Layered double hydroxides (LDHs) are promising photocatalysts but suffer from wide bandgaps and rapid recombination of photogenerated charge carriers, resulting in poor visible‐light activity. Conventional metal nanoparticle sensitization represents a useful means to improve the photocatalytic performance of LDHs, while its mechanism is scarcely understood at the atomic level. Herein, we report a sensitization strategy based on interfacial reactions between metal nanoclusters (NCs) and LDHs to enhance visible‐light‐driven photocatalysis. Au 29‐43 (SG) 27–37 NCs (SG denotes glutathione) were introduced into the regeneration process of MgAl‐based layered double oxides (MgAl‐LDOs), where strong electrostatic interactions between positively charged hydroxide layers and negatively charged carboxylate ligands induced cluster motif reconstruction and size conversion into Au 22 (SG) 18 NCs. The resulting Au 22 /LDH composites exhibit a significantly narrowed bandgap (2.21 eV), extended visible‐light absorption up to 561 nm, and 4.3 times increase in specific surface area. These synergistic effects lead to markedly enhanced photocatalytic degradation of methylene blue, achieving 20.3% removal within 120 min under visible light. Radical scavenging experiments demonstrate that H 2 O 2 and hydroxyl radicals (·OH) are the dominant reactive species in this system. This work demonstrates an effective route for LDHs sensitization and underscores the critical role of interfacial reconstruction in regulating photocatalytic performance.