Non-Covalent Interactions Mimic the Covalent: An Electrode-Orthogonal Self-Assembled Layer

Area of Science:

• Electrochemistry
• Materials Science
• Surface Chemistry

Background:

• Charge-transfer processes at electrified interfaces are crucial for energy conversion, storage, and molecular sensing.
• Current methods rely on covalent tethering, which limits molecularly tunable electrode stability and scope.
• Developing electrode-agnostic strategies is essential for advancing interface control.

Purpose of the Study:

• To introduce a novel synthetic strategy for molecularly defining electrified interfaces.
• To overcome limitations associated with traditional covalent tethering methods.
• To enable versatile and stable molecular control over electrode surfaces.

Main Methods:

• Appending ferrocene redox reporters to amphiphiles.
• Utilizing non-covalent electrostatic and van der Waals interactions for self-assembled layer formation.
• Characterizing the self-assembled layer using voltammetry and in situ infrared spectroscopy.

Main Results:

• A stable self-assembled layer was formed over a 2.9 V range using non-covalent interactions.
• The layer's electrochemical and spectroscopic properties mimicked covalently bound ferrocene.
• The self-assembly process proved reversible and independent of electrode surface chemistry.
• The strategy was successfully demonstrated across diverse electrode materials and morphologies.

Conclusions:

• A synthetic strategy agnostic to electrode surface chemistry was successfully developed for molecularly defining electrified interfaces.
• This non-covalent self-assembly approach offers a versatile, reversible, and stable alternative to covalent tethering.
• The findings pave the way for predictive and non-fouling synthetic control over electrified interfaces, impacting energy and sensing technologies.