摘要
采用周期性密度泛函理论研究羟基化α-石英(101)面的铀酰离子吸附行为.通过对铀酰离子的水合作用考虑水溶剂对结构的短程溶剂化效应,并通过类导体屏蔽模型(COSMO)考虑水溶剂对结构的远程溶剂化效应.吸附能计算结果和电子结构数据均表明水合铀酰离子吸附构型比氢氧化铀酰吸附构型稳定,并且在液相中两种类型的稳定吸附位均为dia-Os1Os2位.两种形式在电子结构上有很大的差异,主要是由于铀与表面作用后成键强弱程度不同,使5f轨道宽化和略微红移存在差异.在铀酰离子吸附的基础上利用卤素离子改变铀酰离子配位环境可调整体系的带隙.
Uranyl ion adsorption on the hydroxylated a-quartz （101） surface was investigated by first- principles density functional theory calculations. We explicitly considered the first hydration shell of the uranyl ion for short-range solvent effects and used the conductor-like screening model （COSMO） for long- range solvent effects. Both the adsorption energies and electronic structures of the adsorption system indicated that the bidentate hydrated uranyl species were more stable than bidentate hydroxylated species, and bidentate adsorption of the uranyl ion on the bridge site of dia-Os1Os2 was the most stable adsorption model in the aqueous state. The large differences in the electronic structures of the two forms were mainly because of the different degree of bonding between uranium and the surface after adsorption, which makes the of orbital narrow and causes a red shift. Use of halogen ions in the uranyl coordination environment can adjust the band gap of the uranyl adsorption system.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2014年第10期1810-1820,共11页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(10676007)
福建省教育厅科研基金(JB14222)资助项目~~
