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A Self-Assembled Organic/Metal Junction for Water Photo-Oxidation
Astrid J Olaya1, Terumasa Omatsu2, Jonnathan C Hidalgo-Acosta1
1Laboratory of Physical and Analytical Electrochemistry, EPFL Valais Wallis , École Polytechnique Fédérale de Lausanne , CH-1951 Sion , Switzerland.
Journal of the American Chemical Society
|April 11, 2019
Summary
We demonstrate self-assembly of TTF and counterions on platinum microparticles, creating p-type semiconductors. Visible light triggers efficient water oxidation, producing O2 and H+, with complete TTF+ reduction.
Area of Science:
- Materials Science
- Electrochemistry
- Photochemistry
Background:
- Developing efficient photocatalysts for water splitting is crucial for sustainable energy.
- Self-assembly offers a pathway to create ordered semiconductor structures with tailored electronic properties.
Purpose of the Study:
- To investigate the in situ self-assembly of tetrathiafulvalene (TTF) derivatives on platinum microparticles.
- To explore the photocatalytic activity of these self-assemblies for water oxidation.
Main Methods:
- In situ self-assembly of TTF, TTF radical cation (TTF•+), and BF4- or PF6- on platinum microparticles in water/acetonitrile mixtures.
- Visible light photoactivation to induce water oxidation.
- Electrochemical characterization of the self-assembled structures.
Main Results:
- Formation of p-type semiconductor self-assemblies on platinum microparticles.
- 100% efficient water oxidation to O2 and H+ upon visible light photoactivation, based on initial TTF•+ concentration.
- Complete photoreduction of TTF•+ to TTF by water.
- Pt microparticles function as floating microelectrodes, with Fermi levels determined by redox species (TTF, TTF•+, HTTF+).
- No decomposition of redox species observed in solution.
Conclusions:
- The self-assembled TTF-based systems on Pt microparticles are effective visible-light-driven water oxidation catalysts.
- The system exhibits high efficiency and stability, with potential for solar fuel production.
- Pt microparticles act as crucial components, mediating electron transfer and stabilizing the catalytic assembly.
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