Structure of nanoporous zirconia-based powders synthesized by different gel-combustion routes

J.R. CASANOVA; I.O. FÁBREGAS; D.G. LAMAS; G.E. LASCALEA; N.E. WALSÖE DE RECA; A.F. CRAIEVICH; C.V. SANTILLI

2005 Activity Report of the Brazilian Synchrotron Light Laboratory

Laboratorio Nacional de Luz Sincrotron (LNLS)

Año: 2006 p. 743 - 743

1518-0204

In this work, the morphology of nanoporous ZrO2-2.8 mol% Y2O3 powders synthesized by different gel-combustion routes, using alanine, glycine, lysine and citric acid as fuels, was investigated by small-angle X-ray scattering (SAXS). Other techniques, such as X-ray diffraction (XRD), environmental scanning electron microscopy (ESEM), transmissionelectron microscopy (TEM) and BET specific surface area measurements, were also employed. Powders prepared with alanine, glycine and lysine exhibit a porous structure consisting of nearly spherical and isolated nanopores with a rather narrow volume weighted radius distribution centred at 30-45Å for calcination temperatures ranging from 600 to 700°C and with a much larger size distribution for higher temperatures (800-900°C). Those synthesized with citric acid exhibit a much wider pore radius distribution for all calcination temperatures. For increasing calcination temperature, both structural entities (nanocrystals and nanopores) are subjected to the same coarsening effect. No significant effects of the nature of the fuel on the crystallite and nanopore morphologies were detected.