Templated Electrosynthesis of Zinc Oxide Nanorods

Electrosynthesis of zinc oxide has been performed in track etched polymer membranes to yield nanorods of defined diameter and controlled length. The electrodeposition process involves two steps: (i) electroreduction of either hydrogen peroxide or nitrate ions to alter the local pH within the pores and (ii) precipitation of the metal oxide within the pores. Synthesis at 22 °C via the reduction of hydrogen peroxide yielded polycrystalline zinc oxide nanorods. When deposition was performed at 90 °C, using the reduction of nitrate to control the local pH, zinc oxide nanorods which displayed the same growth direction along their entire length were obtained. The length of all as-grown rods increased with the integrated charge passed. The growth direction of the ZnO rods obtained at the higher temperature was unusual, being perpendicular to the (101̄1) plane.