Yan Shiwei, Li Yong, Yang Xinyue, Jia Xiaohua, Xu Jingsan, Song Haojie
School of Materials Science & Engineering, Shaanxi University of Science & Technology, Xi' an, Shaanxi, 710021, China.
School of Chemistry and Physics, Queensland University of Technology, Brisbane, 4000, Australia.
Adv Mater. 2024 Mar;36(9):e2307967. doi: 10.1002/adma.202307967. Epub 2023 Dec 13.
The rapid charge recombination, low selectivity for two-electron oxygen reduction reaction (ORR), and limited O diffusion rate hinder the practical applications of photocatalytic H O generation. Herein, a triphase photocatalytic system in which the H O generation occurs at the air-liquid-solid joint interfaces is developed, using polymeric carbon nitride (PCN). The introduction of pyrrole units and cyano group into PCN can promote the activation of oxygen molecules and facilitate the spatial separation of HOMO and LUMO orbits, hence improving the charge carrier separation efficiency and enhancing the formation of H O . Importantly, the gas-liquid-solid triphase interface system allows for the rapid transport of oxygen from the air to the reaction interface, overcoming the low solubility and slow diffusion of oxygen in the water in conventional liquid reaction systems. The triphase system shows a benchmark H O generation rate over PCN-based materials in pure water (2063.21 µmol g h ), which is an approximate tenfold enhancement as compared to powder photocatalyst (215.44 µmol g h ). Simulation and electrochemical tests reveal that the rapid oxygen diffusion rate of triphase interface can promote charge separation and provide more O to generate H O . This work provides a promising strategy for constructing an efficient and sustainable H O production system.
快速的电荷复合、对双电子氧还原反应（ORR）的低选择性以及有限的氧扩散速率阻碍了光催化产H₂O₂的实际应用。在此，使用聚合氮化碳（PCN）开发了一种三相光催化体系，其中H₂O₂的生成发生在气-液-固界面处。将吡咯单元和氰基引入PCN可以促进氧分子的活化，并有助于HOMO和LUMO轨道的空间分离，从而提高电荷载流子的分离效率并增强H₂O₂的生成。重要的是，气-液-固三相界面体系允许氧气从空气快速传输到反应界面，克服了传统液体反应体系中氧气在水中的低溶解度和缓慢扩散。该三相体系在纯水中的H₂O₂生成速率超过基于PCN的材料（2063.21 µmol g⁻¹ h⁻¹），与粉末光催化剂（215.44 µmol g⁻¹ h⁻¹）相比提高了约十倍。模拟和电化学测试表明，三相界面快速的氧扩散速率可以促进电荷分离并提供更多的O₂以生成H₂O₂。这项工作为构建高效且可持续的H₂O₂生产系统提供了一种有前景的策略。
