THE EFFECT OF HEXAMETHYLENETETRAMINE AND TETRABUTYL AMMONIUM BROMIDE TEMPLATE ON THE LANTHANUM PHOSPHATE SYNTHESIS

LaPO₄ synthesis through the sol-gel method and synthesis of LaPO₄ with the addition of templates through the hydrothermal method have been successfully carried out. The templates used are hexamethylenetetramine (HMT) and tetrabutylammonium bromide (TBABr). The concentration of precursor, pH, and aging time in the sol-gel method can affect the structure and morphology of LaPO₄. In this study, the ratio of La³⁺: PO₄^3-, pH, and aging were varied to obtain the optimal condition in used sol-gel method. The optimization results show that LaPO₄ is formed at pH 9, the ratio of moles La³⁺:PO₄ 3-is 1:1, and the aging time is 72 h. The obtained solids were characterized by X-ray diffraction, FTIR, SEM-EDX, and adsorption-desorption N₂. The XRD results showed that LaPO₄ without templates (LaP) and LaPO₄ with TBABr templates (LaPT) had a hexagonal crystal structure, meanwhile, LaPO₄ with HMT templates (LaPH) had a monoclinic crystalline structure. The surface area of LaP, LaPH, and LaPT was 93.28; 69.37; and 107.00 m²/g, respectively, while the pore diameters were 7.04; 16.91; and 8.30 nm, respectively. SEM morphological observations of LaP, LaPH, and LaPT solids are in the form of aggregates that have not been evenly distributed and pore sizes that have not been uniform, and differences are seen between LaP, LaPH, and LaPT.