Abstract:

Nitrobenzene (NB) can seriously damage the ecosystems of water and soil as well as human health. To detect NB efficiently, a microporous luminescent metal-organic framework (MOF) with mixed ligands, Zn₃-MOF, was synthesized by a solvothermal method. Compared to the reported works, the reaction time was reduced by modifying the solution concentration and ratio of reactants. The microporous structure resulting from interpenetration can be beneficial in sensing small organic molecules. Thus, the fluorescent response to commonly used organic small molecules was studied in this work. The results indicate that Zn₃-MOF is highly selective towards nitrobenzene and the fluorescence quenching for NB can be visible with the naked eyes at UV 365 nm. The fluorescence intensity decreases with the increasing concentration of NB and the detection limit can reach up to 10 mg·L^-1. Moreover, this MOF also shows excellent regeneration ability. Fluorescence quenching for NB may be derived from π-π reaction between the framework and NB as well as the electron transfer from the electron-donating framework to the electron-withdrawing group ( NO₂) in NB. These results indicate that Zn₃-MOF can be used as a high-selectivity and high-sensitivity sensor for NB.

Key words: nanomaterials, nitrobenzene, preparation, fluorescence, regeneration

摘要：

硝基苯(nitrobenzene,NB)可以对水体、土壤等生态系统及人体健康造成严重的危害。为了有效地识别和检测硝基苯,制备了一种微孔的荧光金属-有机骨架材料(metal-organic framework,MOF),Zn₃-MOF。通过反应物浓度及比例的调节,反应时间相对于前人工作缩短了一半。该材料在一系列常见有机小分子中的荧光响应结果表明,硝基苯对Zn₃-MOF具有高效的荧光淬灭能力。进一步的系统研究发现,Zn₃-MOF对硝基苯的浓度检测下限可低至10 mg·L^-1,同时具有良好的再生能力。硝基苯对该MOF的荧光淬灭源自其与MOF骨架的π-π作用以及MOF配体向硝基苯的电子转移。这些结果表明Zn₃-MOF是一种高选择性、高灵敏度的硝基苯荧光探针。

关键词: 纳米材料, 硝基苯, 制备, 荧光, 再生