Synthesis and Characterization of Pr-ZrSiO_4 Pigment by a Two-step Method

Nanoscale praseodymium-doped zircon yellowish pigment was prepared by a two-step new method using ZrOCl2.8H2O,Na2SiO3.9H2O and Pr6O11as raw materials.Intermediate nanopowders were hydrothermally synthesized firstly,then these intermediate powders were calcined at high temperatures to produce nanoscale Pr-zircon yellowish pigment.The products were characterized by XRD,TEM,SEM,reflectance spectra and the CIE L*a*b* parameters.The pH of hydrothermal solution,the hydrothermal temperature and the heat treatment temperature are main factors that influenced the quality of pigment.Low pH is favorable for decreasing the calcination temperatures and producing the pigment with good dispersion and homogeneous sizes.The product with best pigment performance is obtained at the reaction conditions as follows,pH=3.5 of hydrothermal solution,hydrothermal temperature of 220℃ and heat treatment temperature of 900℃.