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

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.