TEM study of TiO2 nanocrystals with different particle size and shape

TiO2 anatase nanocrystals deposited on carbon films from colloidal solutions have been characterized using transmission electron microscopy (TEM). The TiO2 nanocrystals exhibit different sizes, shapes, and facets, depending on the pH value and the type of organic additives in the colloidal solutions. Typically, high pH value results in small cubic-like nanocrystals with {112} and {103} faces, while low pH value leads to truncated tetragonal nanocrystals with {101}, {001} and {010} faces. Excess dilution of the particle density appears to cause partial dissolution of the cubic-like TiO2 nanocrystals to form spherical nanocrystals. (C) 2000 Elsevier Science B.V. All rights reserved.