Highly sensitive colorimetric detection and effective adsorption of phosphate based on MOF-808(Zr/Ce)

Abstract

A phosphate ion (Pi) is usually considered as an important index of eutrophication in water and can cause great harm to the water ecological environment. In this work, MOF-808(Zr/Ce) was synthesized simply for phosphate detection and removal. MOF-808(Zr/Ce) with oxidase-like activity can oxidize 3,3′,5,5′-tetramethylbenzidine (TMB). The colorimetric sensing of phosphate was performed based on the enhancement of the oxidase-like activity of MOF-808(Zr/Ce). The linear detection range for phosphate detection was 11–581 μM, and the detection limit (LOD) was 3.7 μM. The MOF-808(Zr/Ce)/CNF (cellulose nanofibers) flexible film synthesized by the filtration method also enables the rapid identification of phosphate. Besides, the phosphate adsorption performance of MOF-808(Zr/Ce) was also investigated. The adsorption capacities are 54.9, 65.1, and 68.5 mg g⁻¹ at 298, 308, and 318 K, respectively. The results show that MOF-808(Zr/Ce) has great potential for phosphate detection and removal.