Design of mesoporous alumina-ceria films on glass: Compositional tuning leads to mesoscopic transformations

We report the first synthesis of 3D ordered cubic mesoporous alumina-ceria films on glass using the triblock copolymer F127 as a structure directing agent. Aluminium tri-sec-butoxide partially chelated with acetyl acetone and cerium nitrate were used as alumina and ceria precursors, respectively, and the concentration of ceria in alumina was varied from 0 (pure Al) to 100 (pure Ce) mol%. Symmetry of mesopores and structural morphologies were tuned simply by alumina/ceria compositional control. The mesophase transformation from cubic Im (3) over barm to Ia3d symmetries occurred when the concentration of cerium nitrate was increased from 0-1 mol% to 5-8 mol%; while higher ceria loadings resulted in the formation of phase segregated alumina-rich spheres embedded in a ceria-rich matrix. The mechanism of the evolution of mesoscopic transformations were established by transmission SAXS studies of the alumina-ceria sols and GIXRD, FESEM, TEM, FTIR and Raman analysis of the films. The crystalline nature of alumina-ceria films with respect to different ceria loadings heat-treated at 400 and 800 degrees C were also reported. (C) 2014 Elsevier Inc. All rights reserved