Metal-Free Covalent Organic Frameworks for Photocatalytic CO2 Reduction

Abstract

Carbon dioxide (CO₂), a major greenhouse gas, is undoubtedly in urgent need of mitigation as its concentration in the atmosphere is rising at an alarming rate, leading to numerous environmental consequences, most notably the serious problem of climate change. Researchers are, therefore, looking for different ways to reduce carbon dioxide. In this article, the use of atmospheric CO₂ gas as a C1 feedstock is a prominent approach, as the effective conversion of CO₂ into fuels can provide a viable option to produce several industrial organic fuels. Among the various types of photocatalysts, covalent organic frameworks (COFs) have garnered significant interest because of their well-defined structures, durable frameworks, intrinsic porosity, and promising photocatalytic performance. Consequently, extensive research has been conducted to explore the photocatalytic capabilities of COFs in the field of CO₂ reduction. Therefore, this comprehensive article highlights the latest developments and advances in metal-free COF-based photocatalytic CO₂ reduction. It also outlines and compares different types of linkers used as COF building blocks, which are highly efficient in the CO₂ reduction reaction. The article concludes with an overview of the current challenges and potential directions for future research in the field of COF-based photocatalysis.