Preparation of Eu(iii) acetylacetonate-doped well-defined titania particles with efficient photoluminescence properties

Abstract

The aggregation/dispersion of luminescent species is a critical factor that determines their luminescence properties. In this study, europium(iii) acetylacetonate (Eu(acac)) was doped into a titania matrix to form Eu(acac)-doped titania particles with well-defined size and shape through a microreactor-based sol-gel approach. The morphology and structure of the as-synthesized products were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, scanning transmission electron microscopy and X-ray diffraction measurements. The Eu/Ti value of the products varied in the range from 0.125 to 5.0 and the resulting luminescence properties were examined. It should be noted that there was an optimum Eu/Ti value that exhibited the strongest luminescence. A possible reason for this phenomenon can be explained on the basis of a balance between the inter-molecular distance of Eu(acac) and its doped amount. The effects of the crystal phase of the titania matrix on luminescence behavior were also investigated. As a result, Eu(acac)-doped amorphous titania demonstrated more efficient luminescence than that after calcined at 550 °C for 6 h to convert amorphous to anatase probably because of the aggregation of Eu species on the crystallite surface. The stability of the present Eu(acac)-doped titania was confirmed by preparing thin films on a glass substrate and by applying UV/ozone treatment. As compared to bare Eu(acac), degradation in luminescence was suppressed in the case of Eu(acac)-doped titania. Thus, the present titania-based hybrid with controlled Eu(acac) doping is useful as a stable, luminescent material for optical, biological and environmental applications.

Synthesis and characterization of Eu3+ doped TiO2 thin films deposited by spray pyrolysis technique for photocatalytic application

“…It is evident that the crystal lattice distortion rises with doping, as we predicated because of insertion of Eu +3 ions into the TiO 2 structure. Similar results were observed by Pal .et al 39 The microstrain (ε) of the prepared un doped and TiO 2 : Eu 3+ thin films can be calculated from the relation (13): 40 (13) It is observed that microstrain decrease with increasing doping concentration, which imply decrease in defect, is due to the motion of the interstitial atoms from their grain boundary to the crystals.…”

“…However, Amorphous titania particles doped with Eu(III) acetylacetonate with atypical molar Eu/Ti ratios are elaborated at concentration of Eu = 0.125, 0.5, 2.0 and 5.0 using sol gel method was studied. 13 It was observed that ideal Eu/Ti value (0.5) that displayed greatest luminescence. Moreover, the Eu (acac) 3 doping is suitable for optoelectronic, organic, and environmental purposes.…”

Preparation of Monodispersed Nanoporous Eu(III)/Titania Loaded with Ibuprofen: Optimum Loading, Luminescence, and Sustained Release

“…To meet all these demands, fluorescent nanoporous amorphous titania submicron particles with a narrow particle size distribution can be a promising DDS carrier. Titania is known as a bioinert ceramic − and thus has been used for biomedical applications − through the formation of a nanoporous structure which allows for accommodating fluorescent species. In general, DDS carriers are required to be water dispersible at around the biological pH range (pH = 7) and to achieve the controlled release of drug molecules.…”

“…To overcome this barrier, we have employed a microfluidic technique which enabled us to obtain well-defined titania–octadecylamine (ODA) hybrid submicron particles containing various functional units. More specifically, the titania–ODA hybrid particles have been functionalized with such species as fluorescein, iron­(III) acetylacetonate, and europium­(III) acetylacetonate (Eu­(acac) 3 ) . Furthermore, ODA is removed from the hybrid particles to form nanoporous amorphous titania submicron particles and realize the improved dispersibility in biological solution .…”

“…More specifically, the titania−ODA hybrid particles have been functionalized with such species as fluorescein, 19 iron(III) acetylacetonate, 20 and europium(III) acetylacetonate (Eu(acac) 3 ). 21 Furthermore, ODA is removed from the hybrid particles to form nanoporous amorphous titania submicron particles and realize the improved dispersibility in biological solution. 24 However, both the fluorescent property and the drug loading into the nanoporous submicron particle carrier have not been achieved so far with the monodispersed amorphous titania.…”