Solar overall water-splitting by a spin-hybrid all-organic semiconductor.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38871750.
- Also identified by DOI 10.1038/s41467-024-49511-7 and PMC identifier 11176302.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Direct solar-to-hydrogen conversion from pure water using all-organic heterogeneous catalysts remains elusive. The challenges are twofold: (i) full-band low-frequent photons in the solar spectrum cannot be harnessed into a unified S<sub>1</sub> excited state for water-splitting based on the common Kasha-allowed S<sub>0</sub> → S<sub>1</sub> excitation; (ii) the H<sup>+</sup> → H<sub>2</sub> evolution suffers the high overpotential on pristine organic surfaces. Here, we report an organic molecular crystal nanobelt through the self-assembly of spin-one open-shell perylene diimide diradical anions (:PDI<sup>2-</sup>) and their tautomeric spin-zero closed-shell quinoid isomers (PDI<sup>2-</sup>). The self-assembled :PDI<sup>2-</sup>/PDI<sup>2-</sup> crystal nanobelt alters the spin-dependent excitation evolution, leading to spin-allowed S<sub>0</sub>S<sub>1</sub> → <sup>1</sup>(TT) → T<sub>1</sub> + T<sub>1</sub> singlet fission under visible-light (420 nm~700 nm) and a spin-forbidden S<sub>0</sub> → T<sub>1</sub> transition under near-infrared (700 nm~1100 nm) within spin-hybrid chromophores. With a triplet-triplet annihilation upconversion, a newly formed S<sub>1</sub> excited state on the diradical-quinoid hybrid induces the H<sup>+</sup> reduction through a favorable hydrophilic diradical-mediated electron transfer, which enables simultaneous H<sub>2</sub> and O<sub>2</sub> production from pure water with an average apparent quantum yield over 1.5% under the visible to near-infrared solar spectrum.