Self-floating COF-based Janus film: A robust triphase interface boosting charge separation for efficient H2O2 photosynthesis

Ying Li, Yuxin Zhang, Wenjie Shi, Chao Zhang, Qinbai Yun, Zongyang Liu, Fuli Ye, Jun Guo, Qingle Yuan, Wenqiang Li, Miao Wang, Xiaotao Zhang, Wenping Hu, Kuo Yuan*, Di-chang Zhong*, Tongbu Lu

H   2   O   2   photosynthesis, as a gas-liquid-solid reaction, faces two giant challenges, i.e., charge recombination and sluggish oxygen transport. For improving efficiency, it is a feasible strategy to construct a robust triphase interface with optimized charge kinetics. Herein, we constructed a self-floating covalent-organic framework (COF)-based film with Janus heterostructure, i.e., COF-[NH   2   -GO]. In overall H   2   O   2   photosynthesis, COF-[NH   2   -GO] exhibited the highest yield among COF film and powder, signifying improved separation and transfer of photogenerated carriers. The photocatalytic triphase system achieved 5,306.6 μmol·m   −2   ·h   −1   H   2   O   2   yield, higher than that of diphase counterpart, ascribed to the promoted O   2   delivery. It was demonstrated that excellent photocatalytic performance was attributed to the improved charge kinetics and mass transfer. A prototypical film-based device was designed for photosynthesis and collection of H   2   O   2   , which exhibited bactericidal activity against   Escherichia coli   . More importantly, this strategy could be extended to other COFs and functional nanomaterials. This work provides new insights for challenging triphase photocatalysis.

https://doi.org/10.1016/j.matt.2026.102679