Tailored Photoactivity of 2D Nanosheets Synthesized by Electron Irradiation of Metal-Organic Ru(II) Monolayers

Abstract

Two-dimensional materials gain significant interest for applications in light harvesting and sensing due to their unique properties and low dimensions. A key challenge is the introduction of specific functionalities such as photoactivity as well as their adjustment. Using adaptable coordination compounds as building blocks for 2D nanosheets offers a promising approach for the controlled optimization of these functionalities. In this study, we demonstrate the preparation of carbonaceous 2D materials by self-assembling thiolated Ru(II) polypyridine complexes (RuSH) onto gold surfaces, followed by electron beam-induced crosslinking into nanosheets. The modular design of the complexes enables the variation of substituents on the bipyridine ligands, thereby influencing the nanosheets’ mechanical stability and photoactivity. Spectroscopic analysis confirms that both the Ru(II) core and thiol group remain mostly intact during crosslinking, facilitating a future post-functionalization for catalysis applications. The resulting nanosheets, with areas up to cm² and thicknesses below 1 nm, exhibit outstanding electrochemical and optoelectrical activity, making them promising candidates for catalysis, sensing, and miniaturized devices.