Low-dimension confinement effect in COF-based hetero-photocatalyst for energy-conversion application

Abstract

Covalent organic framework (COF) materials have aroused tremendous interest in photocatalytic applications due to their tunable pore structure and photoelectric properties. The regular nanopore of COF itself presents a strongly confinement effect, which provides a unique regulatory effect for photons, electrons, protons, and other quantum-scale reaction groups. However, due to the weak surface electron coupling and transfer ability between the reactive groups and basic elements of its structural units, the activity of pure COFs photocatalyst is still not satisfactory. Therefore, the confinement modification strategy of confining low-dimension entities within COFs has been proposed, thus realizing new active sites construction and band structure regulation has been intensively studied, but yet to be summarized systematically. In this paper, the semi-conductivity of COFs is discussed dialectically based on photocatalytic thermodynamics, and the influence of internal linkage motifs and stacking behaviors on the band structure is collected. Then, the basic understanding of confinement characteristics and their influence on photocatalytic performance in dynamics is further explained according to the spatial dimension classification of low-dimension entities. And the application and mechanism of these COF-based confined catalysts in energy conversion reactions are discussed in detail. Lastly, the current challenges and development prospects of COF-based confined hetero-photocatalysts are discussed.

Keywords

band structure / confinement modification strategy / covalent organic frameworks / energy-conversion

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