Preparation and characteristics of FePO_4·xH_2O powder

摘要

Nano-sized precursor FePO_4·xH_2O particles were obtained by oxidation co-precipitation using FeSO_4·7H_2O, H_2O_2 and ammonia. The powder was characterized by differential thermal analysis (DTA) and thermogravimetry (TG), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The TG-DTA results determined the content of crystal water of FePO_4·xH_2O, i.e. x = 1.5. The SEM observation suggested that FePO_4·xH_2O particles were spherical in shape and its grain size was about 150 nanometers. The dispersion of the synthesized powder was improved through the addition of surfactant. The XRD analysis indicated that the synthesized FePO_4·xH_2O was amorphous. After being calcined at 720 °C for 10 hrs, the synthesized FePO_4·xH_2O at pH of ~3.5 was crystallized and FePO_4 in a single phase was obtained. According to the test results, the optimized preparation process parameters were determined.