Role of Cyclic Ether and Solvent in a Non-Alkoxide Sol−Gel Synthesis of Yttria-Stabilized Zirconia Nanoparticles

Abstract

The effects of cyclic ether (epoxide versus oxetane), solvent, and drying method were examined for a non-alkoxide sol−gel synthesis of yttria-stabilized zirconia (YSZ). YSZ sol−gel materials, from 3 to 25 mol % Y2O3, were successfully prepared with either propylene oxide (PO) or trimethylene oxide (TMO) in both aqueous and mixed ethanol−water solutions of Zr4+ and Y3+ chlorides. Supercritical drying (aerogels) produced fine, nanoparticulate networks, whereas drying under ambient conditions (xerogels) resulted in heterogeneous micrometer-sized hard agglomerates. The resulting materials were characterized using powder X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy, scanning electron microscopy, nitrogen adsorption/desorption analysis, and elemental analysis by inductively coupled plasma−atomic emission spectroscopy. The cyclic ether and solvent were found to be critical factors in the resulting as-prepared aerogel surface area and morphology. For a given solvent, aerogels prep...