【摘要】 采用X射线光电子能谱技术（XPS）原位研究CO₂气体与清洁金属铀表面的相互作用机理。贫化铀试样在XPS分析真空室中经氩离子枪溅射蚀刻得到清洁金属铀表面。分别观测U4f_7/2,Ols和Cls光电子峰随CO₂气体暴露剂量的变化,分析表面各元素化学状态的变化和表面化学反应过程。实验表明,CO₂气体首先在清洁金属铀表面解离吸附形成碳粒子、氧粒子和碳氧粒子等。吸附解离的产物导致金属铀表面形成UO₂,UC和自由碳粒子并可能生成碳酸铀。讨论了CO₂气体与清洁金属铀表面的相互作用机理,并与以前研究的O₂和CO气体与清洁金属铀表面反应的现象与机理进行了比较。更多还原

【Abstract】 The adsorption of GO2 on "clean" depleted polycrystalline uranium metal surface has been studied by X-ray photoelectron spectroscopy (XPS) at 300 K. The "clean" surface were prepared by Ar+ ion sputtering under ultra-high vacuum (UHV) condition with a base pressure 6.7Xl0-8 Pa. The results shows that adsorption of CO2 on "clean" uranium metal took place in total dissociation, and leads to the formation of uranium dioxide, uranium carbides and free carbon. The total dissociation of CO2 produced carbon, oxygen species, CO2/2- and CO2/3-species. The diffusion tendency of carbon was much stronger than that of oxygen, and led to form a carbide in oxide-metal interface while the oxygen remained on their surface as an oxide.更多还原