Solar overall water-splitting by a spin-hybrid all-organic semiconductor

Authors: Xinyu Lin, Yue Hao, Yanjun Gong, Peng Zhou, Dongge Ma, Zhonghuan Liu, Yuming Sun, Hongyang Sun, Yahui Chen, Shuhan Jia, Wanhe Li, Chengqi Guo, Yiying Zhou, Pengwei Huo, Yan Yan, Wanhong Ma, Shouqi Yuan, Jincai Zhao

Published: 2024-06-13

DOI: 10.1038/s41467-024-49511-7

Source: Full article


Abstract

AbstractDirect 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 S1 excited state for water-splitting based on the common Kasha-allowed S0 → S1 excitation; (ii) the H+ → H2 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 (:PDI2-) and their tautomeric spin-zero closed-shell quinoid isomers (PDI2-). The self-assembled :PDI2-/PDI2- crystal nanobelt alters the spin-dependent excitation evolution, leading to spin-allowed S0S1 → 1(TT) → T1 + T1 singlet fission under visible-light (420 nm~700 nm) and a spin-forbidden S0 → T1 transition under near-infrared (700 nm~1100 nm) within spin-hybrid chromophores. With a triplet-triplet annihilation upconversion, a newly formed S1 excited state on the diradical-quinoid hybrid induces the H+ reduction through a favorable hydrophilic diradical-mediated electron transfer, which enables simultaneous H2 and O2 production from pure water with an average apparent quantum yield over 1.5% under the visible to near-infrared solar spectrum.