Recent developments in the photocatalytic applications of covalent organic frameworks: A review

Covalent Organic Frameworks (COFs) are crystalline covalent polymers with a high surface area and stable porosity. The synthesis of COFs has significantly progressed with a very high potential for functionalization. Novel and advanced COF materials have gathered significant interest among researchers in this field due to their wide range of useful applications. Using COFs or COF-linked hybrid materials as photocatalysts is a rapidly developing area of research because they provide an exciting and challenging avenue for researchers to make scientific contributions to the preparation and photochemical application of COFs. In this review, the synthetic approaches and recent advances in the photocatalytic applications of COFs are presented. Various photocatalytic applications of COFs are discussed, including heterogeneous photocatalysis covering the topics of photocatalytic degradation and photocatalysis for organic transformations, carbon dioxide reduction and conversion into valuable materials and hydrogen evolution via water splitting. The maximum calculated quantum yield and space-time yield of 5.23E-03 molecules photon−1 and 5.41E-04 molecules photon−1 mg−1, respectively, were demonstrated by the 2D porphyrin-based Por-sp2c-COF for the selective oxidation of amines to imines under visible light irradiation. Altogether, COF-based materials with diverse functionalities have prospects toward a range of environmental, industrial and commercial applications.