Three-dimensional graphene/titanium dioxide composite for enhanced U(VI) capture: Insights from batch experiments, XPS spectroscopy and DFT calculation. (August 2019)

• Record Type: Journal Article
• Authors: Yu, Shujun; Wei, Dongli; Shi, Lei; Ai, Yuejie; Zhang, Pan; Wang, Xiangxue
• Is Part Of: Environmental pollution. Volume 251(2019)
• Page Start: 975
• Page End: 983
• Publication Date: 2019-08
• Subjects: Three-dimensional graphene -- Titanium dioxide -- Uranium -- Spectrum analyses -- Theoretical calculation; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2019.04.127
• Languages: English
• ISSNs: 0269-7491

Abstract

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/TiO2 ) 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/TiO2 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/TiO2 (441.3 mg/g) was observed to outperform the GO (280.0 mg/g), rGO (140.9 mg/g) and TiO2 (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/TiO2 revealed good removal performance for uranyl ions, which showed a great potential application to control the nuclear industrial pollution. Graphical abstract: Image 1 Highlights: 3D GA/TiO2 composite was prepared via a facile and green method. Synergistic effects improved the capture ability for U(VI) on 3D GA/TiO2 than GO, rGO and TiO2 . The adsorption energy of U(VI) onto 3D GA/TiO2 was calculated to be 1.60 eV. Interaction mechanism was electrostatic interaction and inner-sphere surface complexation. Abstract : Three-dimensional graphene/titanium dioxide nanoparticle hybrids (3D GA/TiO2 ) were fabricated and revealed excellent removal properties for uranyl ions.