A bifunctional Zn(II) coordination polymer for fluorescence recognition towards hazardous matters and its high adsorption removal of dye pollutant

Abstract

In this work, a novel Zn(II) coordination polymer (denoted as Zn-CP) was constructed by the mixed ligands of 6-(3′,4′-Dicarboxy phenoxy)isophthalic acid (H4L) and 4,4′-bis(imidazolyl)biphenyl (bib) under solvothermal method. And based on the Zn-CP, the surfactant agent sodium dodecyl sulfate (SDS) was further introduced into the structure, thus obtaining the Zn-CP(S) which possessed the same phase but a smaller size compared with the Zn-CP. Interestingly, the Zn-CP(S) presented a significantly ameliorated fluorescent intensity, about 4.36 times higher than that of the Zn-CP prepared in the absence of SDS. Taking advantage of the improved fluorescence trait of the Zn-CP(S), a fluorescence recognition towards hazardous matters was further carried out. The results showed that Zn-CP(S) could simultaneously recognized for Hg2+, Cr2O72− and a broad range of hazard nitroaromatic explosives with the satisfactory limits of detection (LODs). In addition, Zn-CP could also be used as a recyclable adsorbent to remove methyl orange (MO) in aqueous medium. The maximum equilibrium adsorption capacity of Zn-CP for MO was 61.01 mg/g, and the adsorption mechanism could be attributed to the weak inter-molecular interaction involved π-π stacking and hydrogen bonding between Zn-CP and the MO molecule. Therefore, the bifunctional material has potential application prospects in fluorescence recognition and adsorption.