Hydrothermal Preparation of Ba<sub>1-x</sub>Sr<sub>x</sub>TiO<sub>3</sub> Nanopowder and Its Application in Photocatalytic Degradation of Dye

钛酸锶钡Ba1−xSrxTiO3 (BST)由于具有优异的物理化学稳定性和良好的铁电、介电性能广泛应用于电容器、化学传感器等领域。本文通过调控前驱物的浓度和钡锶钛成分比等合成条件，制备了BST纳米级粉体材料。发现通过增加前驱体的浓度可以有效促进Ba1−xSrxTiO3的形成，在低浓度时会生成BaTiO3或BaTiO3和SrTiO3的混合相粉末。在前驱体中增加锶的用量有利于Ba1−xSrxTiO3空心球颗粒的生成，在溶剂中加入乙醇会抑制Ba1−xSrxTiO3空心球的形成。将所制备的Ba1−xSrxTiO3粉体用于光催化降解亚甲基蓝染料溶液，发现Ba1−xSrxTiO3空心球和商用TiO2粉体P25混合用于光催化降解染料具有协同增效作用。Ba1−xSrxTiO3催化剂的光催化效果优于BaTiO3。 Ba1−xSrxTiO3 has excellent physical and chemical stability, as well as good ferroelctric and dielectric properties, and thus it has been widely applied in capacitor, chemical sensor etc. In this work, we prepared BST nanopowders by changing synthesis conditions, such as the concentration of precursors and ratio of Ba, Si, and Ti. It is found that Ba1−xSrxTiO3 inclined to form at higher con-centration of precursors, while at low concentration, BaTiO3 or mixture of BaTiO3 and SrTiO3 was synthesized. Increasing Sr content is good for the preparation of Ba1−xSrxTiO3 hollowsphere, while addition of alcohol as solvent prevented the formation of Ba1−xSrxTiO3 hollowsphere. The Ba1−xSrxTiO3 nanopowder has good photocatalytic activity towards organic dye methyl blue. The synergistic effect between Ba1−xSrxTiO3 hollowsphere and P25 enhanced the photocatalytic activity comparing to single photocatalyst. The photocatalytic activity Ba1−xSrxTiO3 is better than that of BaTiO3.