A Water-Stable Luminescent ZnII Metal-Organic Framework as Chemosensor for High-Efficiency Detection of CrVI -Anions (Cr2 O72- and CrO42- ) in Aqueous Solution

Zhao-Quan Yao; Guang-Yu Li; Jian Xu; Tong-Liang Hu; Xian-He Bu

doi:10.1002/chem.201705328

A Water-Stable Luminescent Zn^II Metal-Organic Framework as Chemosensor for High-Efficiency Detection of Cr^VI -Anions (Cr₂ O₇^2- and CrO₄^2- ) in Aqueous Solution

Chemistry. 2018 Mar 2;24(13):3192-3198. doi: 10.1002/chem.201705328. Epub 2018 Jan 4.

Authors

Zhao-Quan Yao¹, Guang-Yu Li¹, Jian Xu¹, Tong-Liang Hu^{1

2}, Xian-He Bu^{1

2

3}

Affiliations

¹ School of Materials Science and Engineering, National Institute for Advanced Materials, Tianjin Key Laboratory of Metal and Molecule-Based Material Chemistry, Nankai University, Tianjin, 300350, P. R. China.
² Key Laboratory of Advanced Energy Materials Chemistry, (Ministry of Education), Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300071, P. R. China.
³ College of Chemistry, Nankai University, Tianjin, 300071, P. R. China.

PMID: 29210125
DOI: 10.1002/chem.201705328

Abstract

A new luminescent Zn^II -MOF with 1D triangular channels along the b axis, namely NUM-5, has been successfully assembled and well characterized, which features good stability, especially in aqueous solution. Interestingly, this compound exhibits a fast, sensitive and selective luminescence quenching response towards Cr^VI (Cr₂ O₇^2- /CrO₄^2- ) in aqueous solution. The detection limits towards Cr₂ O₇^2- and CrO₄^2- ions are estimated to be 0.7 and 0.3 ppm, respectively, which are among the lowest detection limits reported for the MOF-based fluorescent probes that can simultaneously detect Cr₂ O₇^2- and CrO₄^2- in aqueous environment. The possible detection mechanism has been discussed in detail. Moreover, it can be easily regenerated after detection experiments, indicative of excellent recyclability. All these results suggest NUM-5 to be a highly selective and recyclable luminescent sensing material for the quantitative detection of Cr^VI anions in aqueous solution.

Keywords: chemosensor; hexavalent chromium; luminescence; metal-organic-framework; water.