N掺杂TiO_2复合膜中N晶格位置转变

采用磁过滤真空直流阴极弧蒸发工艺在石英基底上沉积N掺杂Ti薄膜，随后将其在马弗炉中以不同的退火温度（100～700℃）热处理制备N掺杂TiO2薄膜，采用X线衍射仪（XRD）、拉曼光谱仪（Raman）、X线光电子能谱（ XPS）和扫描电子显微镜（ SEM）分析表征。结果表明：初始态N掺杂Ti薄膜为包含少量TiN相的Ti薄膜，在300℃退火处理时，N掺杂Ti薄膜直接氧化生成N掺杂金红石相TiO2薄膜。初始态的N掺杂Ti薄膜表面平整、颗粒细密，与基底附着牢固，经700℃退火处理后，TiO2颗粒得到了良好的结晶生长，薄膜厚度增加了60％。当热处理温度为600℃时，N掺杂TiO2复合膜中替代型N开始转变为填隙型N，由于填隙型N具有更高的能级，这种N位置的转变进一步窄化了N掺杂TiO2的能带宽度，提高了对可见光的利用率。

Heteropoly acids of the Keggin type with N-substituted β-amminoethylphosphonic acids as coordinate center

Organophosphorus-heteropolytungstic acids of 1 : 12 of P/W ratio, with N-substituted 2-amminoethylphosphonic acids R2R'N+CH2CH2PO3H- (R = R' = H; R = Me, R' = H; R = R' = Me; R = H, R' = Me2CH; R = H , R' = CH3(CH2)2CH2) as coordinate centers were prepared, and characterized by means of elemental analysis, IR, UV spectroscopy, TG and DSC thermal analysis. The results indicate that these organophosphorous-HPAs possess Keggin type structure, and their stoichiometric formulation is R2R'N+CH2CH2PO3H - ·W12O36 ·nH2O. The organic side chain with the ammino-group R2R'N+CH2CH2- and the phosphono-group-PO3H- participate altogether in the formation of the primary structure of the heteropoly anion. In other words, the entirety of each compound R2R'N+CH2CH2PO3H- is as the core or coordinate center of the heteropoly anions. The number of crystal water in the HPA was affected obviously by the N-substituents of the organo-phosphonic acids.