Growth and Characterization of Ordered PbO2 Nanowire Arrays

Large arrays of PbO2 nanowires having high aspect ratios (length-to-width ratio) were grown by potentiostatic electrodeposition into anodic alumina templates under anodic polarization. Different electrolytic solutions were used in order to obtain nanowires of pure alpha-PbO2, pure beta-PbO2, and a alpha+beta mixture. We have found that, in a lead nitrate bath, a crystallographic structure of nanowires depends on pH; this latter was varied adding diluted nitric acid to the electrolyte. Nanowires of pure beta-PbO2 were obtained at pH 0.6, while mixed alpha-PbO2+beta-PbO2 nanowires were grown at pH 2. Pure alpha-phase was obtained in a bath containing lead acetate at pH 6.6. In all deposition conditions, nanowires present the same morphology: perfectly cylindrical wires having uniform diameters throughout length, with an average value of similar to 210 nm and a population density on the order of 10(13) wires/m(2). Very high aspect ratios were obtained already after 30 min of electrodeposition. (C) 2008 The Electrochemical Society. [DOI: 10.1149/1.2988728] All rights reserved.