钛酸盐中钠离子含量对其水热转化制备TiO_2纳米材料的影响

The effect of the sodium content on the hydrothermal transformation of titanate nanotubes to prepared TiO_2 nanomaterials

采用水热法制备了单晶TiO2纳米材料。用X射线衍射仪和透射电子显微镜对产物的晶相组成和形貌进行了表征。考查了钛酸盐中钠离子含量对其水热转化所得TiO2产物的相组成、形貌和尺寸的影响。当pH值为1,含有钠离子时,得到的是以菱形为主的直径为10nm左右的单晶锐钛矿纳米颗粒,不含钠离子时,得到的产物以单晶锐钛矿纳米颗粒为主,同时含有少量单晶金红石纳米棒。当pH值为4,含有钠离子时,得到的是具有高长径比的单晶锐钛矿纳米棒,宽为60nm左右,长为300～500nm左右,不含钠离子时,得到的是尺寸为20nm×60nm的短纳米棒。同时,探讨了钛酸盐中钠离子的影响机理。

Single-crystalline TiO_2 nanomaterials were synthesized by hydrothermal method and characterized by XRD,TEM and HRTEM.The effects of the sodium content of titanate nanotubes on the phase composition,morphology and size of the obtained TiO_2 nanomaterials were investigated.At pH of 1,single-crystalline anatase nanoparticles with rhombic shape were obtained by hydrothermal transformation of titanate nanotubes with sodium content of 7.34%,whereas single-crystalline anatase nanoparticles in great majority and rutile nanorods in little minority were obtained by hydrothermal transformation of titanate nanotubes without sodium;at pH of 4,single-crystalline anatase nanorods with large aspect ratio were obtained by hydrothermal transformation of titanate nanotubes with sodium content of 7.34%,length of 300-500 nm,width of about 60 nm,whereas short anatase nanorods with size of 20nm×60nm were prepared by hydrothermal transformation of titanate nanotubes without sodium.The possible mechanism was ／presented on the effect of sodium.