Preparation and Characterization of 3D Flower-like La2O3 Nanostructures

In this work, a facile route using a simple solvothermal reaction and sequential heat treatment process to prepare 3D La2O3 flower-like nanostructures without employing templates or matrices for self-assembly is presented. The as-synthesized products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), highresolution TEM (HRTEM), energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TG), differential thermal analysis (DTA), and Fourier transformation IR (FTIR). SEM results demonstrate that the as-prepared flower-like precursor with average size of 5- 7 μm in diameter is composed of numerous nanoplates with a thickness of about 100 nm. Influencing factors such as solvothermal reaction temperature, surfactants, reaction time, and solvents were systematically investigated. 3D flower-like La2O3 nanostructures with many holes on the petals were obtained after calcinations of the flower-like precursor at 800 °C for 4 h. The BET surface area of the flower-like La2O3 nanostructures is 9.98 m2/g. Eu3+ doped flower-like La2O3 nanostructures were also prepared employing the same preparation process. The flower-like La2O3:Eu3+ nanostructures show a strong red emission corresponding to 5D0 -7F2 transition (625 nm) of Eu3+ under ultraviolet excitation (267 nm). The possible formation mechanism for the 3D flower-like precursor was briefly discussed.