Controlled sol-gel nanoassembly of Au₂₅(SR)₁₈ nanoclusters for structural and functional integration

Structural assembly of nanomaterials imparts new and enhanced properties to individual components. The "Sol-gel" approach has been a traditional technique to connect diverse types of materials. Here, 3-mercaptopropyl (trimethoxysilane) (MPTS), a dual-functional ligand, has been employed to assemble one of the popular members of atomically precise nanoclusters-Au₂₅ ^- and connect individual nanoclusters via the formation of the Si(OR)₄ "sol-gel" network during the purification process. Depending on the purification procedure, a particle or film of Au₂₅-SiO₂ was achieved and characterized using different techniques. The obtained superstructures of nanomaterials were utilized as a catalyst for the nitrophenol hydrogenation reaction, revealing a 2.5 times faster reaction rate of Au₂₅-SiO₂-film relative to the particle.