锑烯表面铀、钍、钚的吸附性能研究:线性响应方法结合密度泛函理论  

Study on the adsorption properties of antimonene for U,Th,and Pu:Combination of the linear response approach method and density functional theory

作　　者：吴飞宏 汤贤 成国栋 闫隆[3] 张洋 WU Feihong;TANG Xian;CHENG Guodong;YAN Long;ZHANG Yang(School of Nuclear Science and Technology,University of South China,Hengyang 421001,China;School of Computer Science,University of South China,Hengyang 421001,China;Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China)

机构地区：[1]南华大学核科学技术学院,衡阳421001 [2]南华大学计算机学院,衡阳421001 [3]中国科学院上海应用物理研究所,上海201800

出　　处：《核技术》2023年第7期32-41,共10页Nuclear Techniques

基　　金：国家自然科学基金(No.12275125,No.12175302);湖南省自然科学基金(No.2021JJ20038);湖南省科技创新计划资助项目(No.2021RC3105)资助。

摘　　要：基于密度泛函理论(Density Functional Theory,DFT)研究了锕系元素铀(U)、钍(Th)、钚(Pu)在二维金属材料锑烯表面的吸附特性。采用线性响应法拟合得到描述铀、钚5f轨道电子强格点库仑作用的哈伯德U值分别为2.24 eV和2.84 eV。利用DFT+U计算发现,锑烯难以吸附钚原子(吸附能为负值),而对铀、钍原子具有较强的表面化学吸附以及丰富的稳定吸附位点。铀和钍原子能量上最稳定的吸附位点分别为桥位——孔位之间和孔位,吸附能分别为4.40 eV和3.62 eV。通过电子结构、电荷转移和最高占据态轨道波函数分析发现,铀、钍原子使锑烯的带隙中出现杂质态,并与锑烯之间通过强p-d轨道耦合使其稳定吸附。进一步计算了吸附率随温度的变化,得出铀和钍在锑烯表面的解吸温度分别达到837 K和660 K。结果预示锑烯是一种良好的铀、钍吸附材料,在海水提铀等领域具有潜在应用。[Background]The extraction of uranium(U)and its alternative resources,such as thorium(Th)and plutonium(Pu),from seawater is essential to address the scarcity of terrestrial U resources.The development of a separation material with high adsorption properties is the key to solving this problem.[Purpose]This study aims to reveal the adsorption behavior of actinides(U,Th,and Pu)on the surface of a two-dimensional metal material,antimonene.[Methods]The Hubbard U values,Ueff,were determined for the on-site Coulomb interactions of 5f electrons of U and Pu atoms using the linear response method.Furthermore,the adsorption energy,adsorption configuration,electronic structures,charge transfer,and highest occupied molecular orbital wavefunction of a U,Th,or Pu atom adsorbed on the surface of monolayer antimonene were analyzed using the DFT+U approximation.The variation of the adsorption rate with temperature was further calculated by the equilibrium adsorption rate equation.[Results]The calculated Ueff values of U and Pu atoms are 2.24 eV and 2.84 eV,respectively.The Pu atom is energetically unfavorable to be adsorbed on antimonene(with a negative adsorption energy for each adsorption site),whereas the U and Th atoms exhibit strong chemical adsorption on its surface.Antimonene also offers abundant surficial stable adsorption sites for the U and Th adatoms.The most energetically stable sites for the U and Th adatoms are the B(Bridge)-H(Hollow)site and H(Hollow)site,with adsorption energies of 4.40 eV and 3.62 eV,respectively.The impurity states are generated in the band gap of antimonene upon the adsorption of the U or Th atom,and the strong p-d coupling between the U or Th adatom and antimonene in the impurity states contributes to the strong adsorption of the adatoms.The desorption temperatures of U and Th on the surface of antimonene reach 837 K and 660 K,respectively.[Conclusions]The results indicate that antimonene is an excellent two-dimensional adsorbent material for U and Th and has potential for several applications

关 键 词：锑烯 锕系元素 密度泛函理论 线性响应 吸附 电子结构 

分 类 号：TL12[核科学技术—核能科学]