Unlocking Topological Effects in Covalent Organic Frameworks for High-Performance Photosynthesis of Hydrogen Peroxide.

Covalent organic frameworks (COFs) offer a compelling platform for the efficient photosynthesis of hydrogen peroxide (HO). Constructed with diverse topologies from various molecular building units, COFs can exhibit unique photocatalytic properties. In this study, three π-conjugated 2D sp carbon-linked COFs with distinctly different topologies (hcb, sql, and hxl) are designed to investigate the topological effect on the overall photosynthesis of HO from water and oxygen. Despite their similar chemical and band structures, the QP-HPTP-COF with hxl topology outperformed other COFs in the photosynthesis of HO, demonstrating a remarkable solar-to-chemical conversion efficiency of 1.41%. Comprehensive characterizations confirmed that the hxl topology can substantially improve charge separation and transfer, thereby significantly enhancing photocatalytic performance. This study not only unravels the topology-directed charge carrier dynamics in COFs but also establishes a molecular engineering framework for developing high-performance photocatalysts for sustainable HO production.