Single-Point Linkage Engineering in Conjugated Phthalocyanine-Based Covalent Organic Frameworks for Electrochemical CO2 Reduction

Abstract

Highlights Three novel covalent organic frameworks (COFs) composed of nickel phthalocyanine units and different linkages, including dioxin, piperazine, and dithiine, were successfully constructed. It was found that only a single-point structural variation of the linkage in the COFs could effectively modulate their performance in CO2 reduction reaction, where the piperazine-linked COF achieved a pretty high Faradaic efficiency for CO of 90.7% at a critically low overpotential of 0.39 V. Theoretical calculations indicated that the COF with dioxin linkage stabilized the *COOH intermediate more effectively than the other two NiPc-based COFs.

Keywords

• Conjugated covalent organic frameworks
• Linkage engineering
• Single heteroatom tuning
• CO2 electroreduction