On surface synthesis of new 2D nanostructures based on 4-aminophenol on Cu(110)

Abstract

On-surface chemistry has recently emerged as a research field where the catalytic properties of surfaces are essential tools to synthesize new materials sometimes not accessible with other techniques [1]. This new approach has high potential for technological applications and can be a platform for discovering new low dimensional molecular networks [1-3]. In the present work we employ on-surface chemistry techniques to synthesize a new 2D material following a bottom-up strategy. We study the thermally activated chemical reaction of 4-aminophenol (4-AP) induced by the Cu(110) surface in a UHV environment. 4-AP is a good candidate to be used as building blocks for on-surface chemistry due to the presence of functional groups (-NH2, -OH), each with wide specific chemistry. At room temperature the adsorbed 4-AP molecules form mainly an ordered monolayer (Fig.1a) on the Cu(110) surface. The annealing of this monolayer up to 493K induces new chemical reactions that lead to the formation of polymeric-like structures of 4-AP building blocks (Fig.1b). The use of different surface techniques such as STM, LEED, NEXAFS and XPS allows us to obtain structural information of both systems as well as to provide information on the chemical environment of the atoms. It is confirmed that the use of a combination of surface techniques is an optimal strategy to gain insight into on-surface chemical reactions for developing new routes of synthesis for novel materials.