摘要
为探索无机氧化物矿物质与锕系物种的界面作用和成键本质,设计优化了实验已知稳定的金红石(110)表面纳米团簇(SNCs).计算表明中性和弱酸性溶液中的sol模型比pH较小情况下的sat模型吸附更有利,与实验观察到的提高溶液pH导致铀酰吸附速率降低的结果相一致.能量分解表明,界面吸附主要以轨道吸引作用为主,并伴有少量空间效应贡献.电子密度拓扑分析与吸附能数据给出配合物中相同的U—Osurf键强顺序,而红外光谱则显示出相反的键强顺序.电子结构分析表明,所有水合铀酰-SNCs复合物均具有相似分子轨道性质和能量排列顺序,但是HOMO-LUMO能隙和轨道能量有所差异.因此,solbt模式与水合铀酰离子成键作用最强,且吸附作用也最强.
Hexavalent uranyl ion is the most stable form of uranium in water environment.It has high water solubility and is easy to migrate to many places through water,causing great harm to the environment and human health.This makes it a key species in the disposal of radioactive toxic components from nuclear fuel,spent fuel and nuclear waste.Adsorption is considered to be one of the economical and effective techniques for the removal of uranium and other actinides from aqueous solution.New inorganic nanometer functional materials,such as titania have attracted much attention due to their high specific surface area,abundant oxygen-containing functional groups,easy surface modification and low cost.In this paper,the adsorption behavior of rutile titanium dioxide surface nanoclusters(SNCs)for different coordination uranyl compounds(LU)was studied by relativistic density functional theory(RDFT).The influence of solvation effect around uranyl is discussed,that is,supramolecular water solvation(explicit)and self-consistent reaction field solvation model(implicit)are introduced directly into the ions.The changes of adsorbents,adsorbents and complexes formed by adsorption modes were studied in detail.We designed and optimized the stable rutile(110)surface nanoparticle clusters(SNCs).It is concluded that the sol complexes in neutral and weak acid solutions are more favorable than the sat complexes in the case of lower pH.This is consistent with the experimental observation that the increase of solution pH leads to the decrease of uranyl adsorption rate.The energy decomposition shows that the nature of interfacial adsorption is mainly orbital attraction interactions with a small contribution of steric effects.The topological analysis of electron density and the data of adsorption energy show the same order of U—Osurf bond strength,while the infrared spectrum shows the opposite order of bond strength.The electronic structure analysis shows that all hydrated uranyl-SNCs complexes have similar molecular orbital properties and energy ordering although differing in the HOMO-LUMO gaps and orbital energies.Thus,solbt mode has the strongest bond with hydrated uranyl ion and the strongest adsorption.
作者
赵洪波
乔秀丽
田军
迟彩霞
ZHAO Hong-bo;QIAO Xiu-li;TIAN Jun;CHI Cai-xia(Heilongjiang Provincial Key Laboratory of Environmental Catalysis and Energy Storage Materials,Department of Food and Pharmaceutical Engineering,Suihua College,Suihua 152061,China)
出处
《分子科学学报》
CAS
北大核心
2021年第2期182-188,共7页
Journal of Molecular Science
基金
黑龙江省省属高等学校基本科研业务费基础研究项目(KYYWF10236180204,KYYWF10236180302)
黑龙江省自然科学基金资助项目(LH2020B016)
国家自然科学基金资助项目(21273063),。
