Colloidal synthesis of Au nanomaterials with a controlled morphology and crystal phase via the [Au(i)-oleylamine] complex

Abstract

Colloidal gold (Au) with a fine controlled nanostructure possesses unique physicochemical properties and great potential for a variety of applications. Recently, the crystal phase emerged as an important structural factor of Au nanomaterials in addition to the intensively studied size, shape, dimension, and architecture. Intriguingly, a majority of reports on the crystal phase-controlled colloidal synthesis of Au nanomaterials are based on the [Au(I)-oleylamine] complex, where Au(I) is coordinately attached to oleylamine and then reduced to form Au nanocrystals. However, the formation mechanisms of the unusual crystal phases in these reports remain debatable. This review aims to provide a comprehensive overview of morphology- and crystal phase-controlled synthesis of Au nanomaterials which uses the [Au(I)-oleylamine] complex as the intermediate. The various proposed formation mechanisms of different morphologies and crystal phases are discussed and the uniqueness of the [Au(I)-oleylamine] interaction is highlighted. In addition, the applications of oleylamine-capped Au nanomaterials in catalysis and electronic devices are introduced. After that, perspectives are provided on the challenges and opportunities of this direction.