Preparation and characterisation of nanostructured gadolinia-doped ceria tubes

Abstract

In this work, nanostructured gadolinia-doped ceria tubes (Gd_xCe_1−xO_2−x/2 with x = 0.1 and 0.2) were synthesised following a very simple, high yield procedure and their properties were characterised by XRD and by electron microscopy (SEM and HRTEM). Tubes of both oxide compositions were comprised of nanocrystals that exhibited the cubic phase (Fmm space group). In SEM, the tubes were found to have lengths of around 2 µm, diameters of around 700 nm and wall thicknesses of about 10 nm. The SEM and TEM results showed that individual tubes were composed of a thin sheet of nanoparticles curved round to form the tubular structure. The size of these primary nanoparticles was calculated from the peak-broadening seen in the XRD results. Average crystallite sizes of 7.8 and 9.4 nm were found for Gd_0.1Ce_0.9O_1.95 and Gd_0.2Ce_0.8O_1.9, respectively. Electron microscopy observations confirmed the size range of these nanoparticles by direct observation. The nanostructured Gd_0.1Ce_0.9O_1.95 tubes exhibited a higher value of specific surface area, at 97 m² g⁻¹, than the other composition (61 m² g⁻¹).