Morphologically controlled synthesis of Cu2O nanocrystals and their properties

The ability to prepare inorganic nanocrystals with well-defined morphologies and sharp faces should facilitate the examination of their facet-dependent surface, catalytic, electrical, and other properties. In this review we cover different synthetic methods for the growth of Cu2O nanocrystals with morphological control. Cu2O nanocrystals with cubic, cuboctahedral, truncated octahedral, octahedral, and multipod structures have been prepared mainly by wet chemical, electrodeposition, and solvothermal synthesis methods. Methods used for the formation of hollow Cu2O nanocubes, octahedra, and truncated rhombic dodecahedra are also presented. Morphology of Cu2O nanocrystals can be expanded with the use of gold nanocrystal cores to guide the overgrowth of Cu2O shells. Surface properties of Cu2O nano- and microcrystals with sharp faces have been examined in a few studies. The {1 1 1} faces were found to interact well with negatively charged molecules, while the {1 0 0} faces are less sensitive to molecular charges. Preferential adsorption of sodium dodecyl sulfate molecules on the {1 1 1} faces of Cu2O crystals has been demonstrated via plane-selective deposition of gold nanoparticles on only the {1 0 0} faces. It is expected that the development of improved synthetic methods for Cu2O nanocrystals and more knowledge of their facet-dependent properties should lead to their applications in photoactivated energy conversion and catalysis.