Facile tailoring of titanate nanostructures at low alkaline concentration by a solvothermal route

摘要

Nanostructured titanates with different morphologies such as nanoflakes, nanotubes, and nanofibers have been selectively synthesized by a simple solvothermal treatment of commercial anatase TiO _2 using the mixed water-ethanol cosolvent at low alkaline concentration. The effects of solvothermal temperature, volume ratio of H _2O to C _2H _5OH, amount of NaOH and solvents on the formation of titanate nanostructures have been systematically studied through X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). At low concentration of NaOH solution (the actual concentration of OH - in the solution is only 0.58 M), different titanate nanostructures are achieved by simply changing the volume ratio of H _2O to C _2H _5OH at 180 °C and titanate nanotubes can be synthesized between 100 and 180 °C. A probable formation mechanism is proposed based on XRD, SEM and TEM analysis. The influence of cosolvent on the transformation from anatase TiO _2 to titanate is also investigated.