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.