Two Polyoxometalate-Encapsulated Two-Fold InterpenetratingdiaMetal–Organic Frameworks for the Detection, Discrimination, and Degradation of Phenolic Pollutants

Abstract

Phenols are widely used for commercial production, while they pose a hazard to the environment and human health. Thus, investigation of convenient and efficient methods for the detection, discrimination, and degradation of phenols becomes particularly important. Herein, two new polyoxometalate (POM)-based compounds, [Co 2 (btap) 4 (H 2 O) 4 ][SiW 12 O 40 ] (Co-POM) and [Ni 2 (btap) 4 (H 2 O) 4 ][SiW 12 O 40 ] (Ni-POM) (btap = 3,5-bis(triazol-1-yl)pyridine), are prepared via a hydrothermal synthesis method.The compounds show a fascinating structural feature of a POM-encapsulated twofold interpenetrating dia metal−organic framework. More importantly, besides the novel structures, the compound Co-POM realizes three functions, namely, the simultaneous detection, discrimination, and degradation of phenols. Specifically, Co-POM shows an excellent colorimetric detection performance toward phenol with a detection limit (LOD) ca. 1.32 μM, which is lower than most reported colorimetric detectors for phenol. Also, a new colorimetric sensor system based on Co-POM can discriminate phenol, 4-chlorophenol, and o-cresol with ease. Further, Co-POM exhibits a photocatalytic degradation property for 4-chlorophenol under irradiation of visible light with the highest degradation rate at 62% after irradiation for 5 h. Therefore, this work provides the first example of a POMs-based multifunctional material for achieving the detection, discrimination, and degradation of phenolic pollutants.

One-Step Synthesis of Hollow CoS2 Spheres Derived from Polyoxometalate-Based Metal–Organic Frameworks with Peroxidase-like Activity

“…The XRPD patterns of Co-POM are consistent with those reported in the literature. 58 The 2θ peaks at 27.7, 32.1, 36.1, 39.7, and 54.8°c orrespond to the crystal planes (111), (200), (210), (220), and (311), respectively, of the CoS 2 (JCPDS, no. 41-1471).…”

Decoration of Covalent Polyoxometalate-Organic Frameworks with Pt Nanoparticles and Multiwalled Carbon Nanotubes for Simultaneous Electrochemical Detection of Hydroquinone and Catechol

“…Electrochemical experiments show that the modified electrode has good electrocatalytic activity for the nitrite ion. However, because of their discrete molecular cluster structures, POMs also have problems of high solubility and low specific surface area (less than 10 m 2 g –1 ) , which is very unfavorable in the application of electrochemical sensors. Therefore, in order to overcome this shortcoming, combining POMs with porous organic frameworks has attracted the attention of some researchers. − …”

Two 3D Two-Fold Interpenetrated Dia-Like Polyoxometalate-Based Metal–Organic Frameworks: Synthesis and Sulfide Selective Oxidation Activity

“…At the same time, we also obtained a complex [Co 2 (btap) 4 (H 2 O) 4 ][SiW 12 O 40 ] (Co-POM) isomorphic to complexes 1 and 2, which has been reported. 65 As shown in Figure S10, Co-POM was characterized by infrared and powder analysis. It is worth mentioning that our method of synthesizing this compound is simple and the yield is high.…”