第一性原理研究
(1. 廣西大學(xué) 資源與冶金學(xué)院,南寧530004;
2. 廣西大學(xué) 化學(xué)化工學(xué)院,南寧 530004)
摘 要: 采用基于密度泛函理論的平面波贗勢(shì)法對(duì)含鐵雜質(zhì)閃鋅礦(110)表面電子結(jié)構(gòu)及銅在閃鋅礦表面的吸附進(jìn)行模擬。計(jì)算結(jié)果表明:鐵雜質(zhì)與鋅原子的替換能均為負(fù)值,說(shuō)明鐵很容易替換閃鋅表面的鋅,且該替換反應(yīng)對(duì)位置不敏感;鐵雜質(zhì)的存在導(dǎo)致表面能帶向溶部移動(dòng),且在禁帶中出現(xiàn)由鐵3d軌道的tg和e2g構(gòu)成的雜質(zhì)能級(jí),以及硫3p軌道分裂形成的Tamm表面態(tài)能級(jí);鐵雜質(zhì)還改變了閃鋅礦表面d態(tài)和sp態(tài)電子的分布;鐵雜質(zhì)的存在有利于閃鋅礦表面鋅原子與銅發(fā)生交換反應(yīng),但閃鋅礦表面的鐵不能與銅發(fā)生置換反應(yīng),從而減小閃鋅礦表面與銅發(fā)生交換的總鋅位,降低銅對(duì)閃鋅礦的活化效果。
關(guān)鍵字: 閃鋅礦;鐵雜質(zhì);密度泛出理論;銅活化
(1. College of Resources and Metallurgy, Guangxi University, Nanning 530004, China;
2. College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China)
Abstract:The simulation of Fe doped sphalerite (110) surface and Cu adsorption on the sphalerite surface were performed by using plane wave-pseudopotential approach based on density-functional theory. The results show that the substitution energy for Fe substituted Zn atom are negative which indicate the Fe is easy to substitute Zn atom on sphalerite surface, and substitute reaction is insensitive to the site. The presence of Fe impurity shifts the energy band to deep part. Impurity level composed of tg and e2g of Fe 3d orbital and Tamm surface cased by the splitting of S 3p orbital occur in the band gap. Fe impurity changes the distribution of d state and sp state electrons. The calculation suggests that Fe doping sphalerite (110) surface is favorable for the exchange of Cu with Zn at the first layer, however, the Fe atom on the surface can not be replaced by Cu atom, which reduces the total Zn activation sites of sphalerite (110) surface, and the activation of copper on the sphalerite surface becomes poor.
Key words: sphalerite; iron impurity; density functional theory (DFT); copper activation


