Electrodeposition of ZnO Nanorod Arrays on Transparent Conducting Substrates–a Review

ZnO nanorods (NRs) are promising components in a wide range of nanoscale devices for future applications in photocatalysis, solar cells, optical devices and biochemical sensing. The nanorods in the form of arrays vertically oriented to the substrate may be obtained by electrochemical deposition but morphology of the film is very sensitive to the synthesis conditions. This article provides a comprehensive review on various electrosynthesis procedures developed to obtain the nanorods of desired structure, diameter, density on the substrate.We discuss the growth mechanisms and influence of different parameters such as the type and concentration of Zn2+ and OH− precursors, the value of applied potential or current density on the morphology of obtained ZnO films and the role of various structural modifiers on the shape of ZnO nanostructures. We present a brief analysis of the influence of electrosynthesis conditions and postannealing of the samples on optical and electrical properties of ZnO nanowires deposited on the conducting substrate. A short summary of the practical applications of ZnO nanorods is also provided.