Merging semi-crystallization and multispecies iodine intercalation at photo-redox interfaces for dual high-value synthesis.

Chen, Fei; Bai, Chang-Wei; Duan, Pi-Jun; Zhang, Zhi-Quan; Sun, Yi-Jiao; Chen, Xin-Jia; Yang, Qi; Yu, Han-Qing · Nat Commun · 2024

basic_science · Level V

Where this comes from

Abstract

The artificial photocatalytic synthesis based on graphitic carbon nitride (g-C<sub>3</sub>N<sub>4</sub>) for H<sub>2</sub>O<sub>2</sub> production is evolving rapidly. However, the simultaneous production of high-value products at electron and hole sites remains a great challenge. Here, we use transformable potassium iodide to obtain semi-crystalline g-C<sub>3</sub>N<sub>4</sub> integrated with the I<sup>-</sup>/I<sub>3</sub><sup>-</sup> redox shuttle mediators for efficient generation of H<sub>2</sub>O<sub>2</sub> and benzaldehyde. The system demonstrates a prominent catalytic efficiency, with a benzaldehyde yield of 0.78 mol g<sup>-1</sup> h<sup>-1</sup> and an H<sub>2</sub>O<sub>2</sub> yield of 62.52 mmol g<sup>-1</sup> h<sup>-1</sup>. Such a constructed system can achieve an impressive 96.25% catalytic selectivity for 2e<sup>-</sup> oxygen reduction, surpassing previously reported systems. The mechanism study reveals that the strong crystal electric field from iodized salt enhances photo-generated charge carrier separation. The I<sup>-</sup>/I<sub>3</sub><sup>-</sup> redox mediators significantly boost charge migration and continuous electron and proton supply for dual-channel catalytic synthesis. This groundbreaking work in photocatalytic co-production opens neoteric avenues for high-value synthesis.