Photocatalytic properties of zinc oxide nanorods grown by different methods

A comparison of photocatalytic properties of ZnO nanostructures fabricated by different methods was carried out. The photocatalytic properties of as grown and Ar-iontreated ZnO materials were tested using photocatalytic degradation of an aqueous solution of methyl orange dye serving as a model water contaminant. The reaction rate constants of methyl orange photodegradation for untreated ZnO nanorods grown by the method of gas-transport reactions and hydrothermal method were equal to 5.3 x 10(-5) and 3.7 x 10(-4) s(-1), respectively, whereas for the case of the Ar-ion-treated samples they reached 1.85 x 10(-4) and 5.9 x 10(-4) s(-1), respectively. Based on the analysis of the photoluminescence spectra, it is assumed that the difference in photocatalytic activity is connected with different type of defects predominant on the surfaces of ZnO nanorods grown by the hydrothermal and gas-transport reactions methods. The experimental results show that ZnO nanostructures grown by the hydrothermal method would be promising for producing efficient catalysts.