文献类型：期刊文献

英文题名：Highly efficient U(VI) capture by amidoxime/carbon nitride composites: Evidence of EXAFS and modeling

作者：Hu, Baowei[1];Wang, Huifang[1];Liu, Renrong[1];Qiu, Muqing[1]

机构：[1]Shaoxing Univ, Sch Life Sci, Huancheng West Rd 508, Shaoxing 312000, Peoples R China

年份：2021

卷号：274

外文期刊名：CHEMOSPHERE

收录：SCI-EXPANDED(收录号：WOS:000642944800041)、、EI(收录号：20210609877857)、Scopus(收录号：2-s2.0-85100247683)、WOS

基金：Financial support from National Natural Science Foundation of China (21876115) and Natural Science Foundation of Zhejiang Province, China (LGF20C030001 and LGF21C030001) are acknowledged.

语种：英文

外文关键词：U(VI); Amidoxime; Carbon nitride; EXAFS; Modeling

外文摘要：The recovery of uranium from wastewater and safe treatment of U(VI)-containing wastewater are of great important to ensure the sustainable development of nuclear-related energy. Although abundant studies of U(VI) sorption on various adsorbents have been widely achieved, U(VI) sorption at extreme pH and trace concentration is challenging issues due to limited sorption activity of natural adsorbents. The development of novel materials with highly efficient and excellent selectivity for capturing U(VI) from nuclear-related wastewater and seawater is highly desirable. In this study, amidoxime/carbon nitride (AO/g-C3N4) was fabricated and captured U(VI) under a variety of water chemistry. We demonstrated that AO/g-C3N4 exhibited the high adsorption capacities (312 mg/g at pH 6.8), fast removal equilibrium (>98% at 10 min) and superior selectivity for U(VI) compared with the other radionuclides (e.g., 19.76 mg/g of Cs(I)). In addition, AO/g-C3N4 exhibited the high uranium extraction capacity from natural seawater (9.55 mg/g at saturation time of 5.5 days) compared to vanadium (1.85 mg/g). U(VI) adsorption behavior at different pH can be excellently fitted by the surface complexation modeling with three inner sphere surface complexes (i.e., SOUO2(CO3)(2)(3-), SO(UO2)(3)(OH)(5)(0) and SOUO2+ species). According to XPS (X-ray Photoelectron Spectroscopy) analysis, the strong complexation of U(VI) with AO groups retained in C3N4 nanosheet. The split of U-O-eq2 subshell and the occurrence of U-C shell further demonstrated innersphere surface complexation by EXAFS (X-Ray Absorption Fine Structure) spectra analyses. These results revealed that the high potential of AO/g-C3N4 materials for selective U(VI) capture from wastewater and seawater. (C) 2021 Elsevier Ltd. All rights reserved.