From La2O3 To LaCoO3: XPS Analysis

Nanostructured LaCoO3 powder was prepared by a new approach: cobalt oxide nanoparticles were deposited, by wet impregnation, on the La2O3 surface. The La2O3 support was prepared by precipitation from a basic solution of La(NO3)(3)center dot 6H(2)O. The precipitate was dried at 353 K for 2 h and calcined at 923 K for 6 h in air. Nanostructured LaCoO3 was obtained by wet impregnation of La2O3 with aqueous solutions of Co(NO3)(2)center dot 6H(2)O: [Co/La](nomimal) = 1.0 (nominal atomic ratio is obtained from the precursors weighed quantities). The obtained suspension was maintained under stirring for two days and then kept in rest for one day. Water was evaporated in air and the obtained solid was dried at 353 K for 2 h and at 923 K for 6 h in air. The thermal treatment in air promotes a solid state reaction between La-O and Co-O and then the formation of LaCoO3. (C) 2008 American Vacuum Society.