Construction of Covalent Triazine Framework With D-A1-A2 Configuration via Post-Modification for Photocatalytic Hydrogen Evolution

A D-A 1 -A 2 type covalent triazine framework (CTF) was prepared for the photocatalytic hydrogen evolution (HER). In the resulting CTF-CZ-Bpy 2+ , 9-ethyl-9 H -carbazole (CZ) group is used as the donor, triazine ring as the first acceptor, and cyclic diquat (Bpy 2+ ) moiety as the second acceptor. Both experimental and theoretical results show that the D-A 1 -A 2 structure significantly enhances the efficiency of photogenerated charge separation and transfer. As a result, CTF-CZ-Bpy 2+ demonstrated outstanding photocatalytic HER activity with a yield rate of 31.1 mmol g −1 h −1 , which is 7.8 times higher than that of nonfunctionalized CTF-CZ-Bpy.