Preparation and luminescence properties of Y 2O 3:Er 3+/TiO 2 with high specific surface area

Abstract

The three composites Y 2O 3:Er 3+, Y 2O 3:Er 3+/Yb 3+ and Y 2O 3:Er 3+/TiO 2 were prepared using coprecipitation and sol-gel techniques. Their morphology, specific surface area, porosity, UV-vis. absorption spectra and fluorescence spectra were measured using SEM, TEM, surface analysis, UV-vis. absorption and photoluminescence spectrophotometry. SEM and TEM showed that samples prepared using coprecipitation were dispersed, while Y 2O 3:Er 3+/TiO 2 particles possessed a mesoporous surface and average diameter of about 10 nm. The specific surface area and porosity of Y 2O 3:Er 3+/TiO 2 did not result from the combination of the individual properties of Y 2O 3:Er 3+ and TiO 2. The specific surface area of Y 2O 3:Er 3+/TiO 2 was 135. 991 m 2/g and was 4. 8 times that of Y 2O 3:Er 3+ and 2. 5 times that of Degussa P25 TiO 2. A high specific surface area is conducive for application to TiO 2 photocatalysis. The fluorescence spectra of the three composites exhibited three upconversion emission peaks with maxima at 237, 395 and 467 nm following excitation at 388, 500 and 570 nm, respectively. © 2011 Science China Press and Springer-Verlag Berlin Heidelberg.