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Three-dimensional graphene/titanium dioxide composite for enhanced U(VI) capture: Insights from batch experiments, XPS spectroscopy and DFT calculation.
- Source :
- Environmental Pollution; Aug2019, Vol. 251, p975-983, 9p
- Publication Year :
- 2019
-
Abstract
- Efficient containment and capture of uranium (U(VI)) from aqueous solution is an essential component to ensure socially and environmentally sustainable development. Herein, the three-dimensional graphene/titanium dioxide composite (3D GA/TiO 2) was synthesized and applied as an effective adsorbent to remove U(VI) from wastewater as a function of contact time, temperature, pH and ion strength. The 3D GA/TiO 2 material was characterized by X-ray diffraction, Raman spectroscopy, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The batch experiments results indicated that the adsorption of U(VI) on materials were fitted with the pseudo-second order kinetics and Langmuir models. More specifically, 3D GA/TiO 2 (441.3 mg/g) was observed to outperform the GO (280.0 mg/g), rGO (140.9 mg/g) and TiO 2 (98.5 mg/g) at pH 5.0, which was attributable to the excellent cooperative effects. Furthermore, XPS analyses and DFT calculations confirmed the formation of surface complexes between oxygen-containing group and U(VI) with the U–O bonds length of 2.348 Å (U–O1) and 2.638 Å (U–O2). Meanwhile, the adsorption energy was calculated to be 1.60 eV, which showed a very strong chemisorption during the interaction process. It is believed that the 3D GA/TiO 2 revealed good removal performance for uranyl ions, which showed a great potential application to control the nuclear industrial pollution. Image 1 • 3D GA/TiO 2 composite was prepared via a facile and green method. • Synergistic effects improved the capture ability for U(VI) on 3D GA/TiO 2 than GO, rGO and TiO 2. • The adsorption energy of U(VI) onto 3D GA/TiO 2 was calculated to be 1.60 eV. • Interaction mechanism was electrostatic interaction and inner-sphere surface complexation. Three-dimensional graphene/titanium dioxide nanoparticle hybrids (3D GA/TiO 2) were fabricated and revealed excellent removal properties for uranyl ions. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 02697491
- Volume :
- 251
- Database :
- Supplemental Index
- Journal :
- Environmental Pollution
- Publication Type :
- Academic Journal
- Accession number :
- 136983935
- Full Text :
- https://doi.org/10.1016/j.envpol.2019.04.127