A New Synthesis of BaHPO4 Precipitated by BaCO3-H3PO4-NaOH System at Room Temperature

Barium hydrogenphosphate, BaHPO4 was synthesized for the first time through simple and rapid method using BaCO3-H3PO4-NaOH, pH =9.0 at room temperature for 30 min. The studied BaHPO4 decomposed in a single well-defined stage via deprotonated hydrogenphosphate reactions, revealed by TG/DTG and DSC techniques. The calculated wavenumbers based on DSC peak were comparable with FTIR results, which support the breaking bonds of P-OH (HPO42-) in the deprotonated hydrogenphosphate reactions. The thermodynamic functions (ΔH*, ΔG*, and ΔS*) for the deprotonated hydrogenphosphate reactions calculated from DSC data indicate that the deprotonated HPO42- reaction occur a lower-energy pathway and spontaneous process. The FTIR, XRD and SEM data of the studied BaHPO4 and its decomposed product Ba2P2O7 are also reported.