Preparation, characterization and mechanistic features of zirconia films on bare and functionalized gold surfaces

Abstract

Electrochemical synthesis of microcrystalline ZrO2 at room temperature on bare and functionalized gold surfaces is reported to illustrate the biomimetic conditions of nucleation and growth. ZrO2 films prepared on self-assembled monolayers (SAMs) of pentane-1,5-dithiol (PDT) on polycrystalline gold surfaces reveal a high degree of orientation and a distinct cleavage face, in contrast to monoclinic films, obtained on bare gold surfaces at room temperature. Cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), impedance measurement, current-transients, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to follow the monolayer formation, Zr-attachment on the SAM-modified surface and subsequent difference in nucleation conditions of ZrO2 formation. The role of SAMs in controlling the size and habit during crystallization of ZrO2 is discussed in terms of a proposed reaction mechanism.