杂质对黄铁矿电子性质及反应活性影响的密度泛函理论研究(英文)

采用密度泛函理论计算含有砷、硒、碲、钴或镍等杂质的黄铁矿的结构和电子性质,并采用前线轨道理论讨论含杂质黄铁矿与氧气和黄药的反应活性。杂质的存在使黄铁矿晶胞体积膨胀。钴和镍主要对费米能级附近的能带产生影响,而砷杂质主要对黄铁矿浅部和深部价带产生影响,硒和碲主要影响深部价带。电荷密度分析结果表明,所有的杂质原子都与其周围的原子形成较强的共价相互作用。前线轨道计算表明,砷、钴和镍杂质对黄铁矿的 HOMO 和 LUMO 的影响比硒和碲杂质大。此外,含砷、钴或镍的黄铁矿比含硒或碲的黄铁矿更容易被氧气氧化,而含钴或镍的黄铁矿与黄药捕收剂的作用更强。计算结果与观察到的黄铁矿实际情况相符。

Density functional theory study of influence of impurity on electronic properties and reactivity of pyrite

The electronic property of pyrite supercell containing As, Se, Te, Co or Ni hetero atoms were calculated using density functional theory (DFT), and the reactivities of pyrite with oxygen and xanthate were discussed by frontier orbital methods. The cell volume expands due to the presence of impurity. Co and Ni mainly affect the bands near Fermi levels, while As mainly affects the shallow and deep valence bands, and Se and Te mainly affect the deep valence bands. Electronic density analysis suggests that there exists a strong covalent interaction between hetero atom and its surrounding atoms. By frontier orbital calculation, it is suggested that As, Co and Ni have greater influence on the HOMO and LUMO of pyrite than Se and Te. In addition, pyrite containing As, Co or Ni is easier to oxidize by oxygen than pyrite containing Se or Te, and pyrite containing Co or Ni has greater interaction with collector. These are in agreement with the observed pyrite practice.