Effect of hydrogen and oxygen plasma treatments on the electrical and electrochemical properties of zinc oxide nanorod films on zinc substrates

ZnO nanorod films were synthesised on polished zinc sheets by a hydrothermal method. Non-equilibrium oxygen and hydrogen plasma treatments were applied on these nanorod films to study the induced changes in their semiconducting properties. Donor densities were evaluated by means of Mott-Schottky analysis based on the electrochemical impedance data. In comparison to the as-grown films, hydrogen plasma led to an increase while oxygen plasma led to a decrease of the donor density. The corresponding current density potential curves measured in aqueous electrolytes showed an inhibition of anodic current densities in case of the reductive plasma and an inhibition of cathodic current densities in case of the oxidative plasma. Thereby, corrosion protection properties of ZnO nanorod films can be adapted to the respective application of the coated material. (C) 2011 Elsevier B.V. All rights reserved.