Sol‐Gel Production of Ce 0.8 Gd 0.2 O 1.9 Nanopowders Using Sucrose and Pectin
as Organic Precursors
The gadolinium‐doped ceria ( CGO ) is of great interest as oxide ion conducing solid electrolyte for intermediate and low‐temperature solid oxide fuel cell (SOFC) operation. In this investigation, high‐purity
nanopowders of cerium gadolinium oxide ( CGO , Ce 0.8 Gd 0.2 O 1.9) are synthesized
by sol‐gel method using sucrose as an organic chelating agent and pectin for gelation. The results of this investigation indicate that the final particle size of approximately 8 nm can be obtained after calcination of the predried gel at 500°C for 2 h in ambient air. An
insight in to the calcination process has been obtained by using simultaneous thermogravimetric analysis and differential scanning calorimetry (TGA/DSC). Powder X‐ray diffraction (XRD) confirms that all samples crystallized
as single phase cubic CGO powders with no trace of impurity. The mean crystallite sizes calculated from XRD analysis using Rietveld refinement method agree with the morphological features observed using transmission electron microscopy (TEM).
The nanopowders produced in this study exhibit negligible strain as indicated by Rietveld refinement procedure. The nominal composition of CGO has been found to be in excellent agreement with that determined independently using energy dispersive X‐ray spectroscopy
(EDS) and inductively coupled plasma—atomic emission spectrometry analysis (ICP–AES). The XRD and TEM analyses indicate that there is a significant influence of calcination
temperature on the crystal size, which increases with increasing temperature for a fixed annealing time.