水热法制备纳米结构TiO2的生长机制及表征

将钛片放入NaOH溶液中，用水热法制备了TiO2纳米线阵列薄膜。系统地研究了水热参数对产物的影响以及纳米结构TiO2的生长机制。通过场发射扫描电子显微镜(FESEM)、X射线衍射仪(XRD)、透射电子显微镜(TEM)等对样品进行了表征。结果表明，水热过程中，钛溶解和钛酸盐结晶生长之间的动态平衡决定了产物的结构和形貌。在相同温度下，NaOH溶液浓度降低，水热产物的维度就增加。温度升高会促进钛溶解和钛酸盐扩散，使产物在一维尺度上生长。同时高温使晶体结构更加完整。制备的TiO2纳米线陈列显示了良好的光电性能。

Growth Mechanism and Characterization of Nano-Structured TiO2 Prepared by a Hydrothermal Method

Ti foil was put into the NaOH solution and TiO2 nanowire array films were prepared by a hydrothermal method. The effects of hydrothermal parameters on the nano-structured TiO2 and its growth mechanism were systematically studied. The samples were characterized by FESEM, XRD and TEM. The results show that the dynamic equilibrium between the dissolution of Ti and crystal growth of titanate is the main influencing factor for structures and morphologies of the products. At the same temperature, the decreased concentration of the NaOH solution leads to the increased dimension of the hydrothermal products. The temperature rise can accelerate the dissolution of Ti and the diffusion of titanate, and the products grow along linear dimension. Meantime the high temperature makes more complete crystal structure. The prepared TiO2 nanowire array exhibits good optical and electrical properties.