(Invited) To Prepare 2D Au Nanoplates and Its Controlled Molecular Self-Assembly (MS) Mechanism

Abstract

It is very important to prepare 2D noble-metal nanomaterials, but very little is known about their chemical synthesis at molecular level. In this paper, we found the classic citric (CA) reduction method can prepare 2D Au nanoplates with a large range for 2D size (3-150nm). Furthermore, these 2D Au nanoplates exhibit thin thickness (8-20nm), along with two kinds of single crystal structure as 2D Au (110) –dominated and Au (111) –dominated nanoplates. To explore their preparation, we adjusted the CA reduction kinetic as CA additive→ acetone dicarboxylic acid (DCA) →acetone, revealing the intermediate species of DCA is crucial for nanoplate formation. Our DFT (Density-Functional-Theory) model further clarifies that the DCA has molecular interaction, preferentially transferring 2D clusters (Au3-Au7) towards Au(111) facets though accompanying with some Au (100) facets. These soft-hard interaction help us establish two kinds of controlled MS mechanisms towards (111) –dominated nanoplates and Au (110) –dominated nanoplates, revealing the cluster origination and its essential 2D growth process in nucleation-growth process. Consequently, our preparation for 2D Au nanoplates and controlled MS mechanisms open a gate towards nucleation-growth process, thus having great significance and broad impact for future studies.