Nanostructured titanates were prepared by alkaline hydrothermal treatment of Ti powder and NaOH with different concentrations of NaCl solution. The products were characterized by X-ray diffraction, scanning electron microscopy, (high-resolution) transmission electron microscopy, and ultraviolet-visible absorbance, Fourier-transform infrared, and Raman spectroscopies. The effect on the titanate morphology of different concentrations of NaCl in the hydrothermal reaction system was investigated. In the presence of NaCl, Ti powder treated with NaOH initially formed three-dimensional nanobelt microspheres. Nanobelt growth along the [1 1 0] axis orientation was inhibited, and the nanobelts were transformed into wide nanoplates by radial growth. At high concentrations of NaCl, lamellar nanosheets were exfoliated from the large particles through dissolution-recrystallization, and finally rolled into nanotubes. The nonlinear optical (NLO) properties of different titanate nanostructures were studied using the open-aperture Z-scan technique, and a typical positive NLO effect induced by incident light was observed. (C) 2013 Elsevier B.V. All rights reserved.