Visible-Light-Driven Water Oxidation on Self-Assembled Metal-Free Organic@Carbon Junctions at Neutral pH

Sustainable water oxidation requires low-cost, stable, and efficient redox couples, photosensitizers, and catalysts. Here, we introduce the in situ self-assembly of metal-atom-free organic-based semiconductive structures on the surface of carbon supports. The resulting TTF/TTF center dot+@carbon junction (TTF = tetrathiafulvalene) acts as an all-in-one highly stable redox-shuttle/photosensitizer/molecular-catalyst triad for the visible-light-driven water oxidation reaction (WOR) at neutral pH, eliminating the need for metallic or organometallic catalysts and sacrificial electron acceptors. A water/butyronitrile emulsion was used to physically separate the photoproducts of the WOR, H+ and TTF, allowing the extraction and subsequent reduction of protons in water, and the in situ electrochemical oxidation of TTF to TTF center dot+ on carbon in butyronitrile by constant anode potential electrolysis. During 100 h, no decomposition of TTF was observed and O-2 was from the emulsion while H-2 was in the This work new for a new generation of metal-atom-free, low-cost, redox-driven water-splitting strategies.

Automated summary

The study introduces a new method for sustainable water oxidation using metal-atom-free organic-based semiconductive structures, eliminating the need for metallic or organometallic catalysts. By physically separating the photoproducts in a water/butyronitrile emulsion, extraction and reduction of protons in water and in situ electrochemical oxidation of TTF to TTF center dot+ on carbon can be achieved.