Triazine Vertex-Directed Engineering of Interlayer Interactions in Vinyl-Linked Covalent Organic Frameworks for Enhanced Charge-Carrier Transport and Photocatalytic Activity.

Abstract

A major challenge in the development of high-performance organic photocatalytic polymers is establishing efficient charge-carrier transport pathways. In this study, we propose a molecular design strategy that addresses this issue by enhancing interlayer interactions in two-dimensional vinyl-linked covalent organic frameworks (VL-COFs). This is achieved by incorporating a rigid, planar triazine unit at the framework vertex center. The vertex-centered design promotes stronger interlayer interaction, resulting in well-aligned π-stacked columns that facilitate efficient charge-carrier transport and markedly improve the photocatalytic activity. The resulting VL-COFs exhibited outstanding hydrogen peroxide (H₂O₂) production rates and excellent long-term stability in pure water. Moreover, the optimized electronic structure accelerates the rate-limiting O₂-to-OOH* step in the two-electron oxygen reduction reaction, thereby improving the catalytic performance in H₂O₂ synthesis. This work demonstrates a vertex design strategy for tuning interlayer interactions in COFs, offering a promising pathway for developing highly efficient photoactive materials for artificial H₂O₂ photosynthesis.