A multifunctional magnetic core-shell fibrous silica sensing probe for highly sensitive detection and removal of Zn2+ from aqueous solution

摘要

In the present work, a multifunctional core-shell magnetic fibrous silica sensing probe AQ-Fe3O4@SiO2@KCC-1 was prepared for the detection, adsorption and removal of Zn2+. The core was composed of superparamagnetic Fe3O4 nanodots, while the shell consisted of fibrous silica molecular sieve KCC-1 and was decorated by a quinoline derived probe. The multifunctional inorganic-organic hybrid material was characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, N-2 adsorption-desorption, thermogravimetric analysis, and vibrating sample magnetometry. Its sensing performance towards Zn2+ was then discussed in detail. The experimental results suggested that this functional material exhibited enhanced fluorescence in the presence of Zn2+ ions and a high selectivity for Zn2+ over the competing metal ions in aqueous solution. The binding ratio of the AQ-Fe3O4@SiO2@KCC-1-Zn2+ complexes was determined from the Job plot to be 1 : 1. The association constant was calculated to be 1.85 x 10(5) M-1, with a detection limit of 1.08 x 10(-7) M. Furthermore, the adsorption process of Zn2+ on the magnetic fibrous silica composite AQ-Fe3O4@SiO2@KCC-1 was well described by the Langmuir isotherm equation and the equilibrium adsorption capacity is 157.2327 mg g(-1). These results indicate that these multifunctional magnetic fibrous silica sensing materials may find potential and favorable applications for simple detection and efficient removal of Zn2+ in toxicological and environmental fields.