<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Pure ZnO and Ce-doped (5 at.%) ZnO aerogels were prepared by dissociation of dihydrate zinc acetate and cerium nitrate in methanol, followed by drying in supercritical conditions of the solvent. The concentration of zinc acetate solution and the atomic ratio Ce/Zn were fixed at 0.2 mol/L and 0.05 mol/L, respectively. XRD results showed a hexagonal wurtzite structure of ZnO aerogel crystallites and a formation of a separate second phase of ceria cubic phase with fluorite structure and 7.4 nm in size. The introduction of cerium in the solution had a negative effect on the aerogel crystalline quality. The crystallites size was found to be 16 nm in pure ZnO and 27 nm in Ce-doped ZnO aerogels. The grains of Ce-doped ZnO aerogel had torus shaped morphology with hollow centers, but those of pure ZnO were flattened semispheres. The calculated values of different structural parameters showed that cerium ions introduced into the ZnO lattice occupied interstitial sites and Zn ions substituted Ce ones in ceria lattice during the formation process. FT-IR and UV-Vis absorption spectra have not revealed any particularities due to the presence of cerium atoms in ZnO, indicating that Ce (5 at.%) doping of ZnO crystallites synthesized in supercritical methanol did not strongly affect the optical gap of the semiconductor. Micro-Raman studies confirmed the formation of cubic fluorite structure ceria in ZnO aerogel and showed that Raman active modes of ZnO are amplified with the presence of ceria.</p></abstract>

Pure ZnO and Ce-doped (5 at.%) ZnO aerogels were prepared by dissociation of dihydrate zinc acetate and cerium nitrate in methanol, followed by drying in supercritical conditions of the solvent. The concentration of zinc acetate solution and the atomic ratio Ce/Zn were fixed at 0.2 mol/L and 0.05 mol/L, respectively. XRD results showed a hexagonal wurtzite structure of ZnO aerogel crystallites and a formation of a separate second phase of ceria cubic phase with fluorite structure and 7.4 nm in size. The introduction of cerium in the solution had a negative effect on the aerogel crystalline quality. The crystallites size was found to be 16 nm in pure ZnO and 27 nm in Ce-doped ZnO aerogels. The grains of Ce-doped ZnO aerogel had torus shaped morphology with hollow centers, but those of pure ZnO were flattened semispheres. The calculated values of different structural parameters showed that cerium ions introduced into the ZnO lattice occupied interstitial sites and Zn ions substituted Ce ones in ceria lattice during the formation process. FT-IR and UV-Vis absorption spectra have not revealed any particularities due to the presence of cerium atoms in ZnO, indicating that Ce (5 at.%) doping of ZnO crystallites synthesized in supercritical methanol did not strongly affect the optical gap of the semiconductor. Micro-Raman studies confirmed the formation of cubic fluorite structure ceria in ZnO aerogel and showed that Raman active modes of ZnO are amplified with the presence of ceria.

Effect of cerium on structural and optical properties of ZnO aerogel synthesized in supercritical methanol

Laboratoire de Génie de l’Environnement (LGE)

Materials Science-Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Pure ZnO and Ce-doped (5 at.%) ZnO aerogels were prepared by dissociation of dihydrate zinc acetate and cerium nitrate in methanol, followed by drying in...

Aerogel	D	a	c	c/a	V	L	X_C
	[nm]	[Å]	[Å]		[Å³]	[Å]
pure ZnO	16	3.2551	5.2113	1.600	47.8	1.9806	0.9531
Ce-doped ZnO (5%)	28	3.2519	5.2096	1.602	47.7	1.9791	0.5811

Effect of cerium on structural and optical properties of ZnO aerogel synthesized in supercritical methanol

Article Category: Research Article

Published Online: Sep 16, 2016

Page range: 659 - 664

Received: Jan 08, 2016

Accepted: Jun 29, 2016

DOI: https://doi.org/10.1515/msp-2016-0082

Keywords
ZnO aerogel, supercritical methanol, cerium, XRD, FT-IR

© 2016 M. Meddouri et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Lattice parameters a and c, c/a, D, V, XC and L for different aerogels.

Effect of cerium on structural and optical properties of ZnO aerogel synthesized in supercritical methanol

Article Category: Research Article

Published Online: Sep 16, 2016

Page range: 659 - 664

Received: Jan 08, 2016

Accepted: Jun 29, 2016

DOI: https://doi.org/10.1515/msp-2016-0082

KeywordsZnO aerogel, supercritical methanol, cerium, XRD, FT-IR

© 2016 M. Meddouri et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Lattice parameters a and c, c/a, D, V, XC and L for different aerogels.

Keywords
ZnO aerogel, supercritical methanol, cerium, XRD, FT-IR