碲（001）表面吸附羟基及硫离子的第一性原理计算

First Principles Calculation of Hydroxyl and Sulfur Ions Adsorbed on Te (001) Surface

    摘要
  • 摘要: 采用基于密度泛函理论（DFT）的第一性原理，系统研究了羟基（OH−）和硫离子（S2−）在碲（Te）（001）表面的吸附机理及其协同浸出效应。通过构建Te（001）表面模型，结合吸附能、态密度（DOS）和Mulliken电荷分析，揭示了两种离子在其表面的吸附行为及相互作用规律。研究结果表明：OH−和S2−在Te（001）表面均能形成稳定的化学吸附，其中顶位为最稳定吸附位点，吸附能分别为−1.386 eV和−1.838 eV。S2−的引入显著增强了OH−的吸附稳定性，混合体系下吸附能进一步降低至−2.126 eV，表明二者存在协同作用。态密度分析显示，吸附后O和S的p轨道与Te的p轨道在费米能级附近形成共振峰，证实了O−Te和S−Te化学键的生成。Mulliken电荷分析表明，S2−促进了Te表面电荷的转移，使O−Te键的布居值从0.12增至0.16，S−Te键布居值从0.36增至0.48，进一步验证了协同作用的电子机制。实验结果表明，S2−的加入显著增强了OH−在碲表面的吸附能力，加入S2−后碲的浸出率从43.97%提升至66.13%，证实了协同作用的实际应用价值，而理论计算从微观层面解释了碲浸出率升高是由于S2−的协同浸出作用。本研究通过密度泛函理论揭示了碲浸出过程中NaOH、Na2S及NaOH和Na2S混合体系的表面吸附机理及其协同浸出效应，阐明了S2−对OH−吸附的促进作用机制，为碲的高效浸出提取工艺的优化提供了理论依据。

     

    Abstract: This study employed first−principles calculations based on density functional theory (DFT) to systematically investigate the adsorption mechanisms and synergistic leaching effects of hydroxyl ions (OH−) and sulfide ions (S2−) on the tellurium (Te) (001) surface. A Te(001) surface model was constructed, and adsorption energies, density of states (DOS), and Mulliken charges were analyzed to elucidate the adsorption behaviors and interaction mechanisms. The result sreveal that both OH− and S2− exhibit stable chemisorption on the Te(001) surface, with the top site showing the most stable configurations (adsorption energies: −1.386 eV for OH− and −1.838 eV for S2−). The introduction of S2− significantly enhances the adsorption stability of OH−, as evidenced by a further decreased adsorption energy (−2.126 eV) in the mixed system, confirming their synergistic interaction. DOS analysis demonstrates resonance peaks near the Fermi level between the p orbitals of O/S and Te, indicating the formation of O–Te and S–Te chemical bonds. Mulliken charge analysis shows that S2− promotes charge transfer on the Te surface, increasing the bond populations of O–Te (from 0.12 to 0.16) and S–Te (from 0.36 to 0.48), which validates the electronic synergy. The experimental results show that the addition of S2− significantly enhances the adsorption capacity of OH− on the surface of tellurium. After the addition of S2−, the leaching rate of tellurium increases from 43.97% to 66.13%, which confirms the practical application value of the synergistic effect. The theoretical calculation explains that the increase of tellurium leaching rate is due to the synergistic leaching action of S2− at the microscopic level. This study reveals the surface adsorption mechanism and the synergistic leaching effect of the systems of NaOH, Na2S, and the mixture of NaOH and Na2S during the leaching process of tellurium through density functional theory. It clarifies the mechanism of the promoting effect of S2− on the adsorption of OH−, providing a theoretical basis for the optimization of the high−efficiency leaching and extraction process of tellurium.

     

    • HTML全文
    • 参考文献(32)
    • 相关文章
    • 施引文献
  • 资源附件(0)

/

返回文章
返回