Construction of TiO2-covalent organic framework Z-Scheme hybrid through coordination bond for photocatalytic CO2 conversion

In this work, a covalent organic framework (COF), which is constructed by the building blocks of [5,10,15,20-tetrakis(4-aminophenyl)porphinato]copper(II) (CuTAPP) and p-benzaldehyde, is employed to integrate with TiO2 for the purpose of establishing a Z-scheme hybrid. Within the system, isonicotinic acid performs the role of a bridge that connects the two components through a coordination bond. Further photocatalytic application reveals the hybrid framework is able to catalyze CO2 conversion under simulated solar light, resulting in CO production rate of 50.5 mu mol g (1) h (1), about 9.9 and 24.5 times that of COF and pristine TiO2, respectively. The ameliorated catalytic performance owes much to the porphyrin block acting as photosensitizer that augments the light absorbance, and the establishment of Z-scheme system between the inorganic and organic components that enhances the separation of the carriers. In addition, the chemical bridge also ensures a steady usage and stable charge delivery in the catalysis. Our study sheds light on the development of versatile approaches to covalently incorporate COFs with inorganic semiconductors. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

In this study, a covalent organic framework (COF) was constructed with CuTAPP and p-benzaldehyde, integrated with TiO2 to form a Z-scheme hybrid system. The framework showed enhanced photocatalytic performance in CO2 conversion, attributed to the photosensitizer effect of the porphyrin block and the establishment of a Z-scheme system for carrier separation.