Enhancement of optical properties and dependence of the crystal structure, morphological properties of PrPO4 by microwave-assisted-hydrothermal synthesis

In this paper, PrPO4 nanostructures with hexagonal (rhabdophane phase) and monoclinic (monazite phase) structures were obtained by a microwave-assisted-hydrothermal method and characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Dynamic Light Scattering (DLS) and Reflectance Diffuse Spectroscopy (DRS) and High Resolution Transmission Electron Microscopy (HRTEM). A first study of the experiment was done in order to evaluate the reaction time (130 and 180 °C), synthesis time (15 and 30 min) and sintering temperature (400 and 600 °C). Subsequently, the medium pH was adjusted to 1, 3, 5, 9 and 11 under two previously selected conditions. The results highlight the significant effects exerted by the synthesis parameters on the structure, crystal and particle sizes, morphology type, reaction mechanism as well as on the PrPO4 absorption/transmission region.