Optimization of LaPO4 Synthesis and Characterization by Sol Gel Method

Lanthanum phosphate was successfully synthesized by sol-gel method at room temperature. The effect of pH, mole ratio of La:P, and aging time on Lanthanum phosphate formed were investigated. The optimization showed that Lanthanum phosphate is formed at pH 9, the mole ratio of La³⁺:PO4^3- is 1:1, and the aging time is 72 h. Then, the obtained powder was calcined at 550℃. The structure and chemical bond of the obtained powder were characterized using X-Ray Diffraction and Fourier Transform Infrared (FTIR) spectroscopy, respectively. The surface area was measured using N2 adsorption-desorption method. The morphology was analyzed using scanning electron microscopy (SEM). The XRD result showed that the obtained powder was Lanthanum phosphate which had a monoclinic structure. The FTIR spectra showed the presence of O-H functional at 3700-3450 cm^-1 which was confirmed by the H-O-H bending vibration that appeared at 1650 cm^-1. The peaks at 1040, 616, and 540 cm^-1 indicated the presence of P-O stretching, O=P-O, and O-P-O bending. The N2 adsorption-desorption showed that Lanthanum phosphate formed was mesoporous materials with SBET of 93,28 m²/g. SEM images showed that agglomerated solids with irregular shapes were obtained from the synthesis.