Circumventing bottlenecks in H<sub>2</sub>O<sub>2</sub> photosynthesis over carbon nitride with iodine redox chemistry and electric field effects.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38830881.
- Also identified by DOI 10.1038/s41467-024-49046-x and PMC identifier 11535034.
- 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
Artificial photosynthesis using carbon nitride (g-C<sub>3</sub>N<sub>4</sub>) holds a great promise for sustainable and cost-effective H<sub>2</sub>O<sub>2</sub> production, but the high carrier recombination rate impedes its efficiency. To tackle this challenge, we propose an innovative method involving multispecies iodine mediators (I<sup>-</sup>/I<sub>3</sub><sup>-</sup>) intercalation through a pre-photo-oxidation process using potassium iodide (suspected deteriorated "KI") within the g-C<sub>3</sub>N<sub>4</sub> framework. Moreover, we introduce an external electric field by incorporating cationic methyl viologen ions to establish an auxiliary electron transfer channel. Such a unique design drastically improves the separation of photo-generated carriers, achieving an impressive H<sub>2</sub>O<sub>2</sub> production rate of 46.40 mmol g<sup>-1</sup> h<sup>-1</sup> under visible light irradiation, surpassing the most visible-light H<sub>2</sub>O<sub>2</sub>-producing systems. Combining various advanced characterization techniques elucidates the inner photocatalytic mechanism, and the application potential of this photocatalytic system is validated with various simulation scenarios. This work presents a significative strategy for preparing and applying highly efficient g-C<sub>3</sub>N<sub>4</sub>-based catalysts in photochemical H<sub>2</sub>O<sub>2</sub> production.