Green Synthesis of an Ethylenediamine Hybrid Zinc Germanate Nanoribbon and Its Application in Adsorption and Detection of Uranyl Ions

KeyWord:nanoribbon  hydrothermal synthesis  fluorescence detection  uranyl ions  adsorption

Abstract:

      A kind of novel ethylenediamine hybrid zinc germanate nanoribbons£¨NH2£­Zn2GeO4 NRs£© for adsorption and detection of uranyl ions was synthesized by hydrothermal synthesis£®The structure and optical properties of NH2£­Zn2GeO4 NRs were characterized by transmission electron microscopy£¨TEM£©£¬Fourier transform infrared spectroscopy£¨FTIR£©£¬X-ray photoelectron spectroscopy£¨XPS£©£¬X-ray diffraction£¨XRD£©£¬thermogravimetric analysis£¨TG£©£¬X-ray energy spectrometry£¨EDS£©£¬ultraviolet£­visible absorption spectrum£¨UV£­Vis£© and fluorescence spectroscopy£®The results showed that the NH2£­Zn2GeO4 NRs have a crisscross band structure with good crystallinity and good thermal stability£®Meanwhile£¬the surface of NH2£­Zn2GeO4 NRs contains rich amino groups£¬greatly improving the dispersion of the nanoribbons and facilitating the coordination of UO2+2 with the surface amino groups£¬and then adsorbing UO2+2£®Furthermore£¬the interaction between the ¡ªGe¡ªO¡ªH group on the surface of zinc germanate nanoribbons and UO2+2£¬based on the antenna effect£¬turns on green fluorescence to realize the fluorescence detection of UO2+2£®Therefore£¬the NH2£­Zn2GeO4 NRs could selectively and efficiently adsorb UO2+2£¬and their adsorption of uranyl ions conforms to Langmuir isotherm model£¬with a maximum adsorption capacity of 190 mg/g£®On the other hand£¬a sensitive detection method for UO2+2 was established based on the interaction between UO2+2 and NH2£­Zn2GeO4 NRs£¬which could turn on green fluorescence£¬with a linear range of 0£­45 ¦Ìmol/L and a detection limit as low as 0.202 ¦Ìmol/L£®Results showed that only UO2+2 can make NH2£­Zn2GeO4 NRs solution produce green fluorescence£¬while other ions have no fluorescence enhancement effect£¬indicating that the nano material has high selectivity and strong anti-interference ability£®The method was successfully applied to the concentration analysis of UO2+2 in tap water£¬lake water£¬river water and sea water£®The recoveries for the actual samples ranged from 87.2% to 102%£¬with the relative standard deviations less than 10%£®Therefore£¬the prepared NH2£­Zn2GeO4 NRs could be used for the simultaneous adsorption and detection of UO2+2£¬which has a wide application value in detection of actual water samples.