An active two-dimensional covalent organic framework for persulfate-assisted high efficiency photocatalytic degradation of rhodamine B

Covalent organic frameworks (COFs) have been widely used based on their ordered pore structure, inherent porosity, high specific surface area and excellent stability. Herein, the active two-dimensional COF (named HDU-25) photocatalyst was preformed by the solvothermal method, and the structure and morphology were characterized and analyzed. The effects of key factors on rhodamine B (RhB) degradation by HDU-25 were evaluated. The results showed that under suitable conditions, HDU-25 exhibited an excellent photocatalytic degradation rate of 99.9% for persulfate-assisted photocatalytic degradation of RhB, and HDU-25 also had superior stability and reusability. In addition, the mechanism of RhB degradation was investigated using free radical capture experiments and electron spin resonance (ESR) experimental analysis. The intermediates were detected by high performance liquid chromatography-mass spectrometry (HPLC-MS), and possible degradation pathways were suggested. The results of this research highlight the potential of HDU-25 photocatalysts to degrade organic dyes in wastewater. • An active two-dimensional covalent organic framework HDU-25 was synthesized for PS-assisted photocatalytic degradation of RhB. • The effect of various factors was studied, and the degradation efficiency of RhB could be as high as 99.9% under suitable conditions. • The degradation efficiency of HDU-25 remained efficient and stable after 5 repeated uses. • The intermediate products were detected by HPLC-MS, and the possible degradation pathways of HDU-25 were proposed. • HDU-25 is a promising material for the removal of dye wastewater.