Morphology and Vibrational Modes of Lanthanum Oxide (La2O3) Nanoparticles Prepared with Reflux Routes at Different Reaction Times

In the present work, lanthanum oxide (La2O3) was prepared by the refluxing technique using lanthanum nitrate, urea, and double filtered water at 100 degrees C for various synthesis durations (6, 12, 18, and 24 h) in a water medium. X-ray diffraction (XRD) results suggest that La2O3 belongs to a monoclinic crystalline structure with the average crystallite sizes for La2O3 with 6, 12, 18, and 24 h irradiation samples being determined to be 13.4 nm, 18.7 nm, 22.6 nm, and 27.9 nm, respectively. A scanning electron microscope (SEM) was used to evaluate the morphological merits of the samples. The particle size dimensions of La2O3 are calculated to be 38 nm, 32 nm, 30 nm, and 25 nm for La2O3 with 6, 12, 18, and 24 h irradiation, respectively. The observations of the SEM confirmed that La2O3 was present in nano-sized particles. Fourier transform infrared (FTIR) measurement was used to verify the oxygen groups, and UV-visible spectroscopy was also used to measure absorption spectra. The FTIR spectra showed the La-O bending and stretching vibrations at around 530-620 cm(- 1) and 950-1100 cm(- 1), respectively. Thermal gravimetric analysis (TGA) was used to investigate the temperature response of the as-prepared samples. The initial weight loss around 110 oC may be due to the removal of the adsorbed water molecules. Two peaks around 350 oC and 370 oC are seen in the DTA curve, which is seen through a very high merger weight loss in the sample.