Molecular Anodes for Electrocatalytic Water Oxidation Based on Self-Assembled Bilayers Driven by Electron Transfer...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Solar fuel generation via water splitting requires efficient and stable electrodes.
• Oxide-based materials are crucial but often degrade molecular catalysts.
• Existing methods struggle to combine molecular catalysts with oxide surfaces effectively.

Purpose of the Study:

• To develop a robust electrode for water oxidation by protecting molecular catalysts on oxide surfaces.
• To enable efficient electron transfer between catalysts and electrodes.
• To demonstrate a stable and efficient hybrid molecular anode for solar fuel production.

Main Methods:

• Utilized a supramolecular strategy with self-assembled bilayers.
• Bonded a silanolate with long alkyl chains to the electrode surface.
• Attached long alkyl chains to a water oxidation catalyst for supramolecular interaction.

Main Results:

• Achieved efficient water oxidation catalysis at pH 7 with minimal activity loss.
• Demonstrated sustained performance at 0.40 mA/cm² for 15 hours, yielding over 33,800 turnover numbers (TONs).
• Reported a Faradaic efficiency exceeding 92% with the catalyst maintaining its molecular integrity.

Conclusions:

• The supramolecular approach successfully isolates the catalyst from the oxide surface, enhancing stability.
• Efficient electron transfer is maintained, showcasing the synergy between molecular catalysts and oxide materials.
• This work validates a strategy for creating advanced electrodes for solar fuel generation.