NOVEL SYNTHETIC STRATEGIES FOR ULTRASMALL METAL NANOCLUSTERS: TOWARDS ATOMIC PRECISION

Abstract

In recent years, ultrasmall metal nanoclusters (NCs) with core sizes smaller than 2 nm have emerged as a new direction in nanoparticle research due to their discrete and size-dependent electronic structures and molecular-like properties. Metal NCs are typically stabilized by a particular organic ligand in solution, such as proteins and thiolate ligands. The ligand-protected metal NCs can be denoted as MnLm, where M is the metal, L is the organic ligand, and n and m are specific integers. Synthesis of monodisperse metal NCs (with precise control of n and m) in sufficiently large quantities (up to several hundred micrograms) is necessary for establishing reliable size-property relationships and exploring potential applications, which is, however, unavailable in the current development. This PhD study has developed a versatile and scalable synthetic method which utilized a unique reactive gas, carbon monoxide (CO) to furnish a mild and well-controlled reaction environment for NC growth, in which all NC attributes, including size, structure, composition, and surface ligand, could be precisely controlled.