中文摘要：

采用不同钠源,在水热条件下实现了钙钛矿结构NaTaO3、烧绿石结构Na2Ta2O6以及NaTaO3/Na2Ta2O6异质结型复合光催化剂的可控合成,利用X射线衍射、扫描电镜、高分辨透射电镜、紫外-可见漫反射光谱、荧光光谱和X射线光电子能谱对样品进行了表征,探讨了钠源对所得钽酸钠样品结构的影响.光解水析氢实验结果表明,各钽酸盐的光催化活性顺序为Na-TaO3/Na2Ta2O6〉NaTaO3〉Na2Ta2O6.NaTaO3与Na2Ta2O6间形成的纳米尺度异质结有效抑制了光生电子和空穴的复合,这是其具有最高光解水析氢活性的主要原因.

英文摘要：

Sodium tantalate photocatalysts with a perovskite structure （NaTaO3）, a pyrochlore structure （Na2Ta2O6）, and a nano-heterojunction （NaTaO3/Na2Ta2O6） structure were controllably synthesized using the hydrothermal method. Sodium carbonate, sodium stearate, and sodium acetate were used as precursors, respectively. The physical properties of the as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, ultraviolet visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. The effects of the sodium precursor on the structure of sodium tantalate are discussed. The photocatalytic results indicated that the activity for the H2 evolution half-reaction from water splitting was in the following order： NaTaO3/Na2Ta2O6 NaTaO3 Na2Ta2O6. The highest photocatalytic activity of NaTaO3/Na2Ta2O6 can be attributed to heterojunction formation within the nanoparticles, which significantly enhanced the separation of the electron-hole pairs.