Anchoring Redox Mediator on COFs for Efficient Solar to Hydrogen Conversion.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40867095.
- Also identified by DOI 10.1002/adma.202510193 and PMC identifier 12617040.
- 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
To address severe carrier recombination in Z-scheme heterojunctions, redox mediators such as IO<sub>3</sub> <sup>-</sup>/<sup>I-</sup> or Fe<sup>3</sup>⁺/Fe<sup>2</sup>⁺ are often introduced, yet their dispersion in solution causes instability, low electron transport efficiency and side reactions. Herein, an innovative Fe-coordinated 2D Z-scheme heterojunction composed of TpPa-1-COF (TP1C) and Bi<sub>2</sub>WO<sub>6</sub> (BWO) is developed for efficient photocatalytic H<sub>2</sub> production. Unlike traditional indirect Z-scheme heterojunctions, the Fe<sup>3+</sup>/Fe<sup>2+</sup> mediator is firmly anchored on the skeleton of COFs, thus enhancing recyclability, charge migration and long-lasting stability, which is supported by extended X-ray absorption fine structure (EXAFS) and a range of electrochemical tests. In addition, the formation of 2D Z-scheme heterojunctions not only retains high redox properties but also provides abundant active sites for photocatalytic reactions. Consequently, the photocatalytic H<sub>2</sub> production rate of 25% BWO/Fe/TP1C reaches up to 6.31 mmol·g<sup>-1</sup>·h<sup>-1</sup> without the addition of co-catalysts, being about 28.68 times as high as that of pure COFs and 2.3 folds over that of 25% BWO/TP1C, exceeding a host of COF-based photocatalysts. The findings of this research highlight the potential of novel indirect Z-scheme heterojunctions for advanced photocatalytic applications, offering a new pathway to overcome the limitations of traditional COF-based systems in hydrogen production.