Sol-gel derived structures for optical design and photocatalytic application

Abstract

In this work, we synthesised xerogels embedded in honeycomb porous anodic alumina films of 1-150 μm thickness, with pore diameters of 40-180 nm and cell sizes of 120-250 nm, and investigated their luminescence and photocatalytic properties. Sols with compositions corresponding to alumina, garnet, willemite and titania in porous anodic alumina films were generated. It addition to the photoluminescence properties reported previously, the structures comprising titania xerogels in porous anodic alumina reveal efficient photocatalytic activity resulting in decomposition of an organic dye in an aqueous medium. Development of the xerogel/porous anodic alumina structure towards a matrix X-ray converter is discussed. Terbium luminescence under X-ray excitation, with the most intensive emission band at 542 nm, is observed for the first time under excitation with X-rays and cathode rays for a matrix convertor consisting of a sequence of Tb-doped alumina xerogel layers confined in porous anodic alumina of 1 μm thickness grown on a silicon substrate. © 2011 Elsevier B.V. All rights reserved.