用于荧光检测水中磷酸根的Al-MOFs的制备及其特性

Preparation and Characteristics of Al-MOFs for Fluorescence Detection of Phosphate in Aqueous Environment

检测水中的磷酸根对预防水体富营养化和维护水体质量具有重要意义。分别以去离子水、冰醋酸、N,N-二甲酸甲酰胺(DMF)为溶剂,通过溶剂热法制备了3种铝-金属有机框架(Al-MOFs)荧光材料,并用于磷酸根的荧光检测。通过其结构表征和荧光特性研究,分析溶剂对材料的晶体结构以及与磷酸根作用的荧光特性的影响。结果表明,溶剂会影响晶体的成核速率和生长方向,从而导致Al-MOF的结构形貌和尺寸的不同。冰醋酸在合成过程中,会与配体竞争配位位点参与骨架的形成,导致骨架中配体含量减少,铝含量增加,配体到金属的电荷转移(LMCT)效应减少,荧光强度降低。Al-MOFs与磷酸根作用的荧光特性表明,Al-MOF-2具有最好的检测效果,当磷酸根摩尔浓度在0~150μmol/L时,其荧光增强率与磷酸根浓度存在很好的线性关系(R^(2)=0.993),当磷酸根摩尔浓度为150μmol/L时,荧光增强率能达到1.18。这一新型的Al-MOF材料可用于荧光检测水中的磷酸根,同时机理研究为金属有机框架荧光法检测磷酸根提供了新思路。

Detection of phosphate in aqueous environment is of great significance for preventing eutrophication and maintaining water quality.Three Al-MOF fluorescence materials were prepared by solvothermal method using deionized water,glacial acetic acid,and N,N-dimethylformamide(DMF)as solvents,and used for the fluorescence detection of phosphate.Influence of solvents on the crystal structure and the fluorescence characteristics of the interaction with phosphate of materials were analyzed by their structural characterization and fluorescence characteristics research.Results indicated that solvent would influence the nucleation rate and growth direction of crystal,resulting in difference in structure morphology and size of Al-MOF.Glacial acetic acid would compete with ligands for coordination sites to form the architecture,resulting in the decrease of ligand content and increase of Al content in framework,and ligand-to-metal charge transfer(LMCT)and fluorescence intensity reduced.Fluorescence characteristics of Al-MOFs interacting with phosphate indicated that Al-MOF-2 had the best detection effect.Fluorescence enhancement efficiency had a good linear correlation with the phosphate concentration in the range of 0~150μmol/L(R^(2)=0.993).Fluorescence enhancement efficiency could reach 1.18 when phosphate concentration was 150μmol/L.This novel Al-MOF material can be used for fluorescence detection of phosphate,and mechanism study provided a new idea for MOFs fluorescence detection of phosphate.