Simultaneous Detection and Decontamination of Dichromate Ions: The Fluorescence Response and Photocatalysis of Thiadiazole-Modified Zr-Metal-Organic Frameworks

J Agric Food Chem. 2023 Dec 27;71(51):20575-20584. doi: 10.1021/acs.jafc.3c05409. Epub 2023 Dec 17.

Abstract

The simultaneous analysis and removal of highly toxic hexavalent chromium (Cr (VI)) in contaminated water via an easy method remain a serious task. Based on the guidance of bibliometric analysis, a thiadiazole ligand-modified zirconium metal-organic framework (Zr-MOF) heralds a new and simple approach to Cr (VI) treatment. The concentration can be determined by fluorescence quenching with a low detection limit of 1.4 μM and a high quenching constant of 6.88 × 103 M-1. For the sensing mechanism, the fluorescence intensity of the Zr-MOF decreased rapidly due to the competition of Cr (VI) with the Zr-MOF for absorption excitation energy and the induction of Zr-MOF aggregation. The analysis system also displayed satisfactory stability and applicability. Apart from sensing application, Zr-MOF can convert Cr (VI) to Cr (III), and the reduction rate constant was 0.004 min-1 under irradiation. Therefore, the bifunctional Zr-MOF provided a potential application method for controlling the pollution caused by Cr (VI) in wastewater.

Keywords: Cr (VI); fluorescence quenching; fluorescent probe; luminescent metal−organic framework; photocatalytic reduction.

MeSH terms

  • Chromium
  • Decontamination
  • Fluorescence
  • Ions
  • Metal-Organic Frameworks*

Substances

  • Metal-Organic Frameworks
  • Chromium
  • Ions