Specifics of hydrothermal synthesis of oriented zinc oxide nanorods on metallic zinc substrates

Zinc oxide nanostructures are prepared hydrothermally in the presence of ethylenediamine (EDA). The morphology and photoluminescent properties of final products are studied as functions of synthesis temperature, synthesis time, and EDA concentration. A decrease in EDA concentration to 30% favors the formation of more perfect and more ordered structures. Blank experiments show that hydrothermal synthesis without organic reagents does not produce nanostructures. When samples are sheltered from convective flows in the cell, the rod growth direction is dictated by the grain orientation in the foil. When nanorods are formed under low supersaturations (in the absence of convective flows), oxygen nonstoichiometry arises in the nanorods and appears in photoluminescence spectra as increased peak intensities in the green spectral range.