A porphyrin-based metal–organic framework with highly efficient adsorption and photocatalytic degradation performances for organic dyes

Abstract

Organic dye pollution has become an urgent issue due to their toxicity to humans and potential for damage to the environment. However, achieving highly efficient adsorption and degradation materials for organic dyes remains a huge challenge in practical application. Herein, a new porphyrin-based metal–organic framework (MOF), [Me₂NH₂][Sr₂(TCPP)(OAc)(H₂O)]·2DMA (1, H₄TCPP = tetrakis(4-carboxyphenyl)porphyrin, DMA = N,N′-dimethylacetamide, HOAc = acetic acid), has been synthesized, which possesses two types of one-dimensional channels, and one of them contains Me₂NH₂⁺ counter cations. By virtue of the electrostatic interaction, Me₂NH₂⁺ can be exchanged by cationic dyes to realize the adsorption of cationic organic dyes. For example, this MOF exhibits remarkable adsorption and degradation performances for cationic dyes, in which the removal efficiency exceeds 99% within 3 h for RhB⁺, and the degradation efficiency for MB⁺ reaches 99% within 22 min for 5 cycles, which exceeds most of the reported MOFs. The study on the mechanism of photocatalytic degradation suggests that 1 shows highly efficient reactive oxygen species production, and therefore an excellent photocatalytic activity.