Self-assembly of benzenecarboxylic acids on well-defined noble metals have been intensively investigated using surface sensitive techniques such as scanning tunneling microscopy (STM) - a powerful tool in the study of supramolecular chemistry - the chemistry of the non-covalent intermolecular bonds. However, most studies were focused on the formation of nanostructures via benzene-tricarboxylic and benzene-dicarboxylic acids, which are composed of multiple numbers of carboxylic acid functional groups, allowing to form long range ordered molecular array through COOH-mediated intermolecular hydrogen bonds. Two dimensional nanostructures of benzoic acids comprising of a single carboxylic acid functional group on the phenyl ring at metal-electrolyte interfaces were rarely reported using scanning tunneling microscopy (STM) because only one carboxylic acid for each benzoic acid is available to form intermolecular hydrogen bonds, making it difficult to construct long range ordered nanoscale architectures. In the present work we employed scanning tunneling microscopy (STM) in combination with electrochemical techniques to explore the adsorption and phase formation of benzoic acids at Au(111)/electrolyte interfaces. Our experiments show how electrolyte, molecular concentration, electrochemical potential, co-adsorption of aqueous ions affect the adsorption and self-assembly of benzoic acids. Effect of parameters (electrolyte ions, concentration, potential) revealed in this study will provide valuable information in the formation of molecular adsorption, self-assembly, materials, corrosion inhibition, and molecular devices.

Electrochemical scanning tunneling microscopy studies on the adsorption and assembly of benzenecarboxylic acids at electrode/electrolyte interfaces

2019 Spring National Meeting

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