Boosted charge carrier concentration via luminescent quenching of photoexcited electrons in CdS/FI S-scheme heterostructures for efficient photocatalytic hydrogen production

摘要

One of the key strategies to go beyond the limited hydrogen production efficiency during photocatalytic process is to increase effective charge carrier concentration participating hydrogen evolution reaction (HER). Herein, considering organic luminescent materials as "photo-excited electron factory" with large numbers of exited carriers under light irradiation, 2-Fluorene-4,5-diphenylimidazole/CdS (FI/CdS) S-scheme heterojunction was constructed to modulate charge transfer via extracting abundant of photoexcited electrons in FI as luminescent quenching process. The impeded charge recombination in FI/CdS S-scheme heterojunction gave rise to 6 orders of magnitude higher in carriers concentration and 7.8 times higher in H2 evolution rate for CF20 (9.67 x 1026 cm- 3, 5.28 mmol h-1 g- 1) than that of pure CdS (2.69 x 1020 cm- 3, 0.68 mmol h-1 g- 1). It demonstrates that quenching photo-excited electrons in luminescent component through synergistic organic-luminescent/ semiconductor interaction could be a creative and prominent strategy to enhance photocatalytic performance.

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