Synergistic Structural and Electronic Regulation of Copper-Based Metal-Covalent Organic Frameworks for Improving Bifunctional Photocatalysis

The [3+3]-type TAPT-MCOF with enhanced surface area and favorable mass transport was constructed, accompanied by the [3+2] Dip-MCOF as counterpart. • The electron-deficient-rich design in TAPT-MCOF highly intensify local asymmetric charge distribution and facilitate photogenerated carrier separation. • TAPT-MCOF exhibits significant improvement in dual-photocatalysis, both of the production rate in H 2 O 2 synthesis and CO 2 conversion are higher than Dip-MCOF. Photocatalytic technology is an effective approach to address energy shortages and environmental problems. However, developing efficient and stable multifunctional photocatalysts remains a challenging task. In this study, two metal-covalent organic frameworks (MCOFs) were synthesized using a trinuclear copper cluster as the electron-rich node: TAPT-MCOF with a [3+3] configuration and Dip-MCOF with a [3+2] configuration. In the absence of sacrificial agent, TAPT-MCOF exhibits improved visible-light-driven photocatalytic performance in both hydrogen peroxide (H 2 O 2 ) synthesis and carbon dioxide (CO 2 ) reduction. The H 2 O 2 production rate is 261.8 μmol g -1 h -1 , about 2.4 times that of Dip-MCOF. The reaction rate for CO 2 reduction is also higher than that of Dip-MCOF. The enhanced behavior originates from two synergistic effects: (ⅰ) the specific surface area of TAPT-MCOF in the [3+3] configuration affords favored transport channels for efficient mass migration, including the reactants and products; and (ⅱ) the triazine group with electron-deficient property (EDP) and the trinuclear copper (Cu 3 Py) cluster with electron-rich property (ERP) in TAPT-MCOF create a highly intensified local asymmetric charge distribution, effectively promoting the photogenerated electron-hole separation. This finding provides guidance for designing efficient bifunctional photocatalysts by leveraging the dual structure regulation of porous frameworks. The [3+3] configuration and relatively electron-deficient triazine unit endow TAPT-MCOF with enhanced mass and charge transport, promoting its bifunctional photocatalytic performance for both H 2 O 2 synthesis and CO 2 reduction. Download: Download high-res image (293KB) Download: Download full-size image