Electrochemical Self-Assembly of ZnO Nanoporous Structures

Abstract

ZnO nanoporous structures were prepared on Cu substrates by electrochemical deposition in solutions of ZnCl2 + ethylenediaminetetraacetic acid (EDTA) at a temperature of 90 °C. Cyclic voltammetry was used to study the electrochemical reactions relevant to the film growth. The transfer coefficient and diffusion coefficient of Zn(II) in 0.05 mol L-1 ZnCl2 + 0.01 mol L-1 EDTA at 343 K were calculated as 0.276 and 5.12 × 10-10 m2 s-1, respectively. The synthetic parameters in this research allowed further structural manipulation for ZnO nanoporous films. The morphology evolvement from uniform planar foam structures to bricklike and spherelike foam structures could be realized by changing the current densities of electrodeposition. The PL spectra of the prepared ZnO samples show that few oxygen vacancies or interstitial Zn centers would be formed when the electrochemical deposition was carried out with a low current density (≤0.1 mA/cm2).