A stable multifunctional Zn(Ⅱ) based metal-organic framework for sensitive detection of Hg(II), Cr(VI), nitrobenzene and adsorption of methylene blue

It is well known that Hg(II) and Cr(VI) are highly toxic, and nitrobenzene and methylene blue (MB) are common organic pollutants. Their detection and removal are still a challenge. Herein, a novel metal-organic framework [Zn(CPA)(DMF)]n has been successfully constructed by the strategy of anchoring Zn2+ and rigid ligand 2,5-bis(4′-carboxyphenyl)aniline (H2CPA). The obtained Zn-MOF has large pores and uncoordinated sites. The structure is stable after immersed in pure water for 30 days and in the pH range of 3–12, which results in good sensing and adsorption potential. Experiments show that this Zn-MOF can be used to detect not only Hg(II) and Cr(VI) with high selectivity and sensitivity in pure water，but also nitrobenzene in DMF. The detection mechanisms are studied in detail. In addition, this Zn-MOF displays good adsorption for methylene blue, and the removal percentage is 92.5%.