Rare earth ion-doped CeO 2 has attracted more and more attention because of its special electrical, optical, magnetic, or catalytic properties. In this paper, a facile electrochemical deposition route was reported for the direct growth of the porous Gd-doped CeO 2. The formation process of Gd-doped CeO 2 composites was investigated. The obtained deposits were characterized by SEM, EDS, XRD, and XPS. The porous Gd 3+doped CeO 2 (10 at% Gd) displays a typical type I adsorption isotherm and yields a large specific surface area of 135 m 2 /g. As Gd 3+ ions were doped into CeO 2 lattice, the absorption spectrum of Gd 3+-doped CeO 2 nanocrystals exhibited a red shift compared with porous CeO 2 nanocrystals and bulk CeO 2 , and the luminescence of Gd 3+-doped CeO 2 deposits was remarkably enhanced due to the presence of more oxygen vacancies. In addition, the strong magnetic properties of Gd-doped CeO 2 (10 at% Gd) were observed, which may be caused by Gd 3+ ions or more oxygen defects in deposits. In addition, the catalytic activity of porous Gd-doped CeO 2 toward CO oxidation was studied.

Recently, rare earth (RE) ion-doped CeO 2 has attracted much attention for special optical, magnetic, and catalytic properties. First reported in this paper is a facile electrochemical synthesis of Eu 3+ -doped CeO 2 nanobelts with greatly improved optical properties. The synthesized Eu 3+ -doped CeO 2 nanobelts were characterized by energydispersive spectrometry, scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results of XRD and TEM indicate that Eu 3+ -doped CeO 2 nanobelts were well crystallized and have cubic crystal structures. The XPS results show Eu 3+ and Ce 4+ coexist in these prepared nanobelts and indicate Eu 3+ -doped CeO 2 nanobelts were successfully prepared. The formation mechanisms of Eu 3+ -doped CeO 2 nanobelts were preliminarily investigated. The correlation between the band gap energies and the morphologies of these samples was studied by UV-vis absorption spectrum. The results indicate Eu 3+ -doped CeO 2 nanobelts had an excellent response in the visible region of solar spectrum and showed potential application for solar cells. The photoluminescent properties of Eu 3+ -doped CeO 2 nanobelts were investigated, and the remarkable enhancement of luminescence can be clearly observed because of the rapid increase of oxygen vacancies and their special morphology.

The dendritic crystal growth patterns that typically grow along principal crystallographic axes and have the hierarchical structure have been attracting much attention from scientists for several centuries. Here we report that the ZnO dendritic nanostructure as a new member of the ZnO family could be successfully prepared on Cu substrates by electrochemical deposition in the solution of ZnCl 2 + citric acid at a temperature of 90 °C. Furthermore, our synthetic parameters allow further structural manipulation. The morphology evolvement from dendritic structures to nanorods could be successfully realized when KCl as supporting electrolyte was added to the deposition solution. The green light emission band of the ZnO dendritic structure prepared in 0.05 M ZnCl 2 + 0.05 M citric acid is almost negligible, indicating that these ZnO deposits are highly crystallized and of excellent optical quality. The PL spectra of the as-grown ZnO nanorods show they possess many oxygen vacancies, and the acquired ZnO nanorods have a potential application in sensors.

Here we report the preparation of porous CeO2 and clusters of CeO2 nanosheet arrays via a simple, efficient electrochemical approach. Gas bubbles functioning as a dynamic template were utilized in our research for the synthesis of nanosheet array clusters. The Hc and Mr values of porous CeO2 are almost the same as those of CeO2 nanosheet array clusters at 5 K, and they are about 5916 Oe and 8.83 x 10(-4) emu, respectively. However, the saturation magnetization of CeO2 nanosheet array clusters is much larger than that of porous CeO2 structures. The magnetic property of the prepared CeO2 deposits may be caused by the existence of Ce(III), indicating potential interest in the nanodevices because of their electronic and magnetic properties.

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