Covalent organic framework based photocatalysts for efficient visible-light driven hydrogen peroxide production

Hydrogen peroxide (H2O2), as an important environmentally friendly oxidant, has been widely used in bleaching, disinfection, wastewater treatment and chemical synthesis, while the artificial photosynthesis of H2O2 from H2O and O2 over certain photocatalysts has been considered as a clean and energy-saving approach and has been widely explored in recent years. Covalent organic frameworks (COFs) represent a newly blooming class of crystalline porous materials with periodically ordered structures that possess a set of intriguing features, including diverse structural designability and durability, high porosity and low density, wide light-harvesting ability and semiconducting properties. Benefiting from these particular properties, the blooming developments of COFs in recent years have brought promising impetus for the realization of efficient visible-light driven H2O2 production. Thus, a systematic and comprehensive review is timely to provide constructive guidance for the development and rational design of more efficient COF-based photocatalysts. In this review, the up-to-date application of COF-based photocatalysts for H2O2 photosynthesis was comprehensively summarized and discussed. Firstly, the general background and fundamental principles of COF-based photocatalysts for photocatalytic H2O2 production were briefly introduced, followed by the detailed classification and discussion of the strategies reported thus far for realizing improved photocatalytic performance. In addition, the challenges and prospects of COF-based photocatalysts for visible-light driven H2O2 production were addressed. This review comprehensively summarized and discussed the up-to-date application of COF-based photocatalysts for efficient H2O2 photosynthesis, aiming to provide constructive guidance for the fast development of this field.