物理学报
物理學報
물이학보
2013年
4期
86-92
,共7页
P掺杂%锐钛矿相TiO2%第一性原理
P摻雜%銳鈦礦相TiO2%第一性原理
P참잡%예태광상TiO2%제일성원리
P doping%anatase TiO2%first-principles
利用基于密度泛函理论的第一性原理对不同P掺杂形式(P替位Ti, P替位O,间隙P)的锐钛矿相TiO2的晶格常数、电荷布居、能带结构、分态密度和吸收光谱进行了计算.结果表明, P替位Ti时, TiO2体积减小, P替位O和间隙P的存在使TiO2的体积膨胀;替位Ti的P和间隙P均有不同程度的氧化,而替位O的P带有负电荷.三种P掺杂形式均导致锐钛矿相TiO2禁带宽度的增大,并在TiO2禁带之内引入了掺杂局域能级. P掺杂导致TiO2禁带宽度增大的程度依次为:间隙P>P替位Ti>P替位O.吸收光谱的计算结果表明, P替位Ti并不能增强TiO2的可见光吸收能力,但间隙P的存在大幅提高了TiO2的可见光光吸收能力,间隙P有可能是造成实验上P掺杂增强锐钛矿相TiO2光催化活性的重要原因.
利用基于密度汎函理論的第一性原理對不同P摻雜形式(P替位Ti, P替位O,間隙P)的銳鈦礦相TiO2的晶格常數、電荷佈居、能帶結構、分態密度和吸收光譜進行瞭計算.結果錶明, P替位Ti時, TiO2體積減小, P替位O和間隙P的存在使TiO2的體積膨脹;替位Ti的P和間隙P均有不同程度的氧化,而替位O的P帶有負電荷.三種P摻雜形式均導緻銳鈦礦相TiO2禁帶寬度的增大,併在TiO2禁帶之內引入瞭摻雜跼域能級. P摻雜導緻TiO2禁帶寬度增大的程度依次為:間隙P>P替位Ti>P替位O.吸收光譜的計算結果錶明, P替位Ti併不能增彊TiO2的可見光吸收能力,但間隙P的存在大幅提高瞭TiO2的可見光光吸收能力,間隙P有可能是造成實驗上P摻雜增彊銳鈦礦相TiO2光催化活性的重要原因.
이용기우밀도범함이론적제일성원리대불동P참잡형식(P체위Ti, P체위O,간극P)적예태광상TiO2적정격상수、전하포거、능대결구、분태밀도화흡수광보진행료계산.결과표명, P체위Ti시, TiO2체적감소, P체위O화간극P적존재사TiO2적체적팽창;체위Ti적P화간극P균유불동정도적양화,이체위O적P대유부전하.삼충P참잡형식균도치예태광상TiO2금대관도적증대,병재TiO2금대지내인입료참잡국역능급. P참잡도치TiO2금대관도증대적정도의차위:간극P>P체위Ti>P체위O.흡수광보적계산결과표명, P체위Ti병불능증강TiO2적가견광흡수능력,단간극P적존재대폭제고료TiO2적가견광광흡수능력,간극P유가능시조성실험상P참잡증강예태광상TiO2광최화활성적중요원인.
The lattice parameters, charge populations, band structures, density of states and absorption spectra of P-doped anatase TiO2 are calculated using the first-principles based on the density functional theory. The results indicate that when the Ti atom is substituted for P atom, the volume of TiO2 decreases. When P atom substitutes for O atom or exists as interstitial atom, the volume of TiO2 increases. The substitutional P at Ti site and interstitial P are oxidized to different degrees, and the substitutional P at O site is reduced a little. The different three sites of P doping result in the increase of anatase TiO2 forbidden gap width and the introduction of local doping energy levels. The band gap increasing of P-doped anatase TiO2 is in the following sequence: interstitial P>substitutional P at Ti site>substitutional P at O site. The absorption spectra indicate that the substitutional P at Ti site cannot enhance the visible light absorption ability of the anatase TiO2, whereas the interstitial P strongly enhances the visible light absorption ability of the anatase TiO2. The interstitial P is probably an important reason for the experimental enhancement of the photocatalytic activity of P-doped anatase TiO2.
