Organic polymer facilitated CO₂ photoreduction: a minireview

Continuously increasing fossil fuel consumption with large amounts of CO2 emission has caused huge environmental problems. Photocatalytic reduction of CO2 to value-added fuels and chemicals with light as a clean and renewable driving force is a highly promising route to facing energy and environmental issues. Among all of the proposed photocatalysts, organic polymers as metal-free photocatalysts have been intensively developed for CO2 photoreduction, ascribed to their outstanding CO2 adsorption capacity, photochemical performance, and tunable structure. Recent advances in CO2 photoreduction using functionalized carbon nitride materials, covalent organic frameworks, and conjugated organic polymers as catalysts are discussed in this review. Particular emphasis is put on elucidating the relationship between the organic polymer structure and photocatalytic ability. The corresponding reaction mechanism and reaction pathway are deeply studied as well. Moreover, the opportunities and challenges of the development of polymer-catalyzed CO2 photoreduction are proposed preliminarily.