(1. 廣西大學(xué) 化學(xué)化工學(xué)院，南寧 530004；2. 廣西大學(xué) 資源與冶金學(xué)院，南寧 530004；
3. 廣西民族大學(xué) 化學(xué)化工學(xué)院，廣西高校化學(xué)與生物轉(zhuǎn)化過程新技術(shù)重點(diǎn)實(shí)驗(yàn)室，南寧 530006；
4. 廣西大學(xué) 物理科學(xué)與工程技術(shù)學(xué)院，南寧 530004)
摘 要: 應(yīng)用基于密度泛函理論(DFT)的第一性原理，采用廣義梯度近似(GGA)和平面波超軟贗勢(shì)方法，研究空位缺陷對(duì)氧分子在方鉛礦(100)表面吸附行為的影響，并比較和分析它們及理想表面的Mulliken電荷布居、電子密度差圖和態(tài)密度等。結(jié)果表明：鉛空位比硫空位難形成，兩種空位缺陷表面對(duì)氧分子有強(qiáng)烈的化學(xué)吸附作用，其吸附能均高于理想表面的，說明空位缺陷可以促進(jìn)氧分子在方鉛礦表面的吸附。氧分子在理想表面及鉛空位表面發(fā)生了解離吸附，氧原子與硫原子形成了共價(jià)鍵；氧分子在硫空位表面沒有發(fā)生解離吸附，氧原子與表面的鉛原子表現(xiàn)出較強(qiáng)的離子相互作用力。
關(guān)鍵字: 方鉛礦；空位缺陷；氧分子吸附；密度泛函理論
（1. College of Chemistry and Chemical Engineering , Guangxi University, Nanning 530004, China;
2. College of Resources and Metallurgy, Guangxi University, Nanning 530004, China;
3. Key Laboratory of Chemical and Biological Transformation Process of Guangxi Higher Education Institutes,
School of Chemistry and Chemical Engineering, Guangxi University for Nationalities, Nanning 530006, China;
4. College of Physics Science and Engineering, Guangxi University, Nanning 530004, China）
Abstract:The effects of vacancy defects on oxygen molecule adsorption on galena surface (100) were studied by applying the general gradient approximation (GGA) and plane-wave ultrasoft pseudopotential method based on the first principle of density functional theory (DFT). The Mulliken charges population, electron density difference maps and density of states of oxygen atom and surface atoms before and after O2 adsorption were analyzed. The results show that the formation of Pb-vacancy on the galena surface (100) is more difficult than S-vacancy, and the chemical adsorption of oxygen molecule on both Pb-vacancy and S-vacancy surfaces occurs, and their adsorption energies are more negative than those on the perfect surface, which indicates that vacancy defect can encourage the oxygen molecule adsorption on galena surface. The dissociated adsorption of oxygen molecule occurs on the perfect and Pb-vacancy surfaces, and a covalent bond is formed between oxygen atom and sulfur atom. The oxygen molecule adsorbing on S-vacancy surface is not dissociated. Ionic interaction between oxygen atom and lead atom is very strong.
Key words: galena; vacancy defect; oxygen molecule adsorption; density functional theory
