Controlled synthesis of monodispersed CuO nanocrystals

Controlling the size, shape and structure of nanocrystals is technologically important because of the strong effect of size and shape on optical, electrical, and catalytic properties. Monodispersed nanocrystals of copper oxide were prepared by the precipitation-pyrolysis method. By controlling the starting materials, reactive concentration and annealing temperature, we can obtain spherical monodispersed CuO nanocrystals of different sizes or rodlike CuO nanocrystals. The particle sizes of CuO monodispersed nanocrystals can be tuned in the range between similar to7 and 30 nm. The products have been characterized by x-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy and the UV-visible absorption spectrum. The absorption spectra of CuO nanocrystals show clear evidence of the quantum size effect. The possible formation mechanism of monodispersed CuO nanocrystals is discussed.