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

Abstract

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.