Ta掺杂IrO_2活性氧化物电子结构的DFT分析  

DFT Analysis of Electronic Structure in the Active Oxide of Ta-doped Rutile IrO_2

作　　者：敬熠平 念保峰 王欣[1] 刘雪华[2] 邱宇 周扬杰 林玮[2] 唐电[1,2] 

机构地区：[1]福州大学材料科学与工程学院,福州350108 [2]福州大学材料研究所,福州350002 [3]福建省冶金工业研究所,福州350011

出　　处：《贵金属》2016年第4期15-20,共6页Precious Metals

基　　金：国家自然科学基金(11104031;11374053)

摘　　要：Ta掺杂的Ir-Ta-O是电化学工业中具有代表意义的电极材料。采用基于密度泛函理论(DFT)的投影缀加平面波中的广义梯度近似方法,对金红石型Ir8O16和Ta掺杂的Ir7Ta1O16复合氧化物的晶体和电子结构进行计算。结果表明,Ir O_2的结构数据与文献报导相吻合。掺Ta的Ir7Ta1O16存在2种不同结构,二者晶体结构参数、系统总能和电子结构很接近。Ta掺杂可使Ir8O16晶胞体积增大,使体系相对稳定。掺Ta的(Ir,Ta)O2与Ir O_2类似,也体现金属的导电特性。Ta原子比Ir原子失电子能力强,掺杂后Ta原子周围的电子向O原子转移,为体系提供了更多的离子键。Ta-doped Ir-Ta-O has been used as a benchmark anode material in the electrochemical processes. The lattice structure and the electronic structure of the composite oxide, rutile Ir8O16 and Ta-doped Ir7Ta1O16 were investigated by using the projector augmented wave method （PAW） and generalized gradient approximation （GGA） based on the density functional theory （DFT）. The results suggest that the calculated equilibrium parameters of IrO2 are in good agreement with data in the available literatures. There exist two different structures of Ta doped Ir7Ta1O16, and they have the similar crystal structure, total energy of system and electronic structure. By doping Ta into rutile IrO2, the cell volume increases and the system becomes more stable, and the electrical conductivity of mixed Ir7Ta1O16 is similar to that of IrO2. Ta has greater tendency to lose the electron than Ir and the electrons around Ta transfer to O atoms, forming stronger ionic bonds.

关 键 词：金属材料 密度泛函理论 (Ir Ta)O2 晶体结构 Bader布居 电荷密度 

分 类 号：TG[金属学及工艺]