Liquid phase methods for design and engineering of two-dimensional nanocrystals

Recently, a great need for high-quality two-dimensional nanocrystals appeared. Because of their extraordinary physical and chemical properties, these nanomaterials find various applications in nanotechnology and are of great interest for engineering of advanced materials, particularly heterostructures with the unique properties that cannot be found in natural materials. In response to this demand, different methods for obtaining two-dimensional nanocrystals are developed and chemical synthetic methods are the most universal among them. They provide freedom, variability and functionality to engineering of 2D nanocrystals. The complex formation is known to provide solubility of components of the reaction system and stability of colloidal solutions. Within this context, the present review aims to consider and emphasize the crucial role of complex formation in the synthesis of 2D nanocrystals using soft templates based on amines and carboxylic acids. The methods of synthesis of 2D nanocrystals in the double electrical layer and templated by the perfluorophenyl ligands are summarized and emphasized. Finally, it is shown that the side reactions can significantly change composition of the reaction mixture, but 2D nanocrystals are nonetheless obtained, so the reaction medium is changeable within a wide range.