Adsorption, order, stability, and barrier function of organothiol and organophosphonic acid monolayers on bismuth surfaces (BiMoSta)

• Applicants: Professor Dr.-Ing. Guido Grundmeier; Professor Dr. Wolf Gero Schmidt
• Subject Area: Thermodynamics and Kinetics as well as Properties of Phases and Microstructure of Materials ; Computer-Aided Design of Materials and Simulation of Materials Behaviour from Atomic to Microscopic Scale ; Synthesis and Properties of Functional Materials
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 575166306

Metallic bismuth structures have great potential for application in areas such as sensor technology, secondary batteries, electrochemical seawater desalination, and medical technology. The properties of these bismuth structures in mostly aqueous environments and their stability under operating conditions are strongly influenced by their surface chemistry. It is therefore of great interest to control functional properties and their stability by adsorbing organic monolayers with varying chemical structures and degrees of order. The project combines experimental and theoretical investigations into the molecular functionalization of bismuth with organothiols and organophosphonic acids. In particular, the order and defect density of monolayers of various organothiols and organophosphonic acids will be controlled by adjusting the oxide coverage, the chain length of the molecules, as well as the adsorption time, and their influence on the properties of the Bi surface will be investigated. Through joint experimental and theoretical investigation of the systems, the project aims to gain a fundamental understanding of the structures and processes, which will also enable predictions to be made about the properties of modified Bismuth surfaces. Spectroscopic, microscopic, and electrochemical methods are used to elucidate monolayer adsorption and its order and defect structure as a function of the oxide or metallic termination of the surface and as a function of the functional groups of the monolayers. By calculating surface and interface structures, reaction kinetics, phase diagrams, and spectroscopic signatures, theory supports the understanding of vibrational and electronic spectroscopic data and their interpretation with respect to the structure of the interface, its bonding characteristics, and properties. The analysis of the electrochemical cycle stability of the monolayers and the correlation of chloride incorporation kinetics and metal dissolution with the monolayer structure should lead to the development of predictive models for adsorption, barrier effect, and stability of organic coatings on Bi surfaces.

• DFG Programme: Research Grants