TEM study of TiO_2 nanocrystals with different particle size and shape

摘要

TiO_2 anatase nanocrystals deposited on carbon films from colloidal solutions have been characterized using transmission electron microscopy (TEM). The TiO_2 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 nanocrystal with {101}, {001} and {010} faces. Excess dilution of the particle density appears to cause partical dissolution of the cubic-like TiO_2 nanocrystals to form spherical nanocrystals.