Hybrid materials based on covalent organic frameworks for photocatalysis

Abstract

Covalent organic frameworks (COFs) feature π-conjugated structure, high porosity, structural regularity, large specific surface area, and good stability, being considered as ideal platform for photocatalytic application. Although single COFs have achieved significant progress in photocatalysis benefiting from their distinctive properties, the COFs-based hybrids provide an extraordinary opportunity to achieve superior photocatalytic performance. From the perspective of carrier transfer mechanism, a systematic summary of hybrids based on COFs and other functional materials (metal single atoms, metal clusters/nanoparticles, inorganic semiconductors, metal–organic frameworks, and other polymers) can offer valuable guidance for the design of COFs-based hybrids. In this review, the photocatalytic mechanism for hybrid materials (such as Schottky junction, type II heterojunction, Z-scheme heterojunction, and S-scheme heterojunction) is briefly introduced. Subsequently, the performance of COFs-based hybrids in photocatalytic water splitting, CO₂ reduction, and pollutant degradation are comprehensively reviewed. Specifically, the carrier separation and transfer in different types of hybrids are highlighted. Finally, the challenges and prospects of COFs-based hybrids for photocatalysis are envisaged. The insights presented in this review are expected to be helpful in the rational design of COFs-based hybrids to obtain outstanding photocatalytic activity.