Constructing Synergistic Trlazine and Acetylene Cores in Fully Conjugated Covalent Organic Frameworks for Cascade Photocatalytic H2O2 Production

摘要

Covalent organic frameworks (COFs) are an idealtemplate for photocatalytic H2O2 synthesis because of the tunablechemical structures and semiconductor properties. However, thephotoactivity for COFs is still under-improved due to theinefficient intrinsic charge generation, fast recombination ofphotogenerated charges, and limited electron transport along theframeworks. Herein, spatially separated and synergistic triazine andacetylene units are first integrated into COFs (EBA-COF andBTEA-COF) for photocatalytic H2O2 production. The spatialseparation of triazine and acetylene cores leads to efficient chargeseparation and suppressed charge recombination, and C=Clinkage facilitates electrons transport over the skeletons. Bothexperimental and computational results suggested that triazine andacetylene units synergistically promote H2O2 synthesis in a two-electron pathway. The EBA-COF showed an attractive activity with aH2O2 production rate of 1830 uxnol h~(-1) g_(cat)~(-1) superior to that of most other COF-based catalysts. This study provides a method fordesigning photocatalysts with synergistic photocatalytic active sites based on vinylene-linked COFs.