Synthesis, Characterization, and NIR Reflectance of Highly Dispersed NiTiO₃and NiTiO₃/TiO₂Composite Pigments

Abstract

The highly dispersed nanostructured NiTiO 3 pigments and NiTiO 3 /TiO 2 composite pigments can be synthesized at relative low temperature. The activation energy of crystal growth of NiTiO 3 during calcinations via salt-assistant combustion method is 9.35 kJ/mol. The UV-vis spectra results revealed that the absorbance decreased with the increasing of calcinations temperature due to small size effect of nanometer particles. The optical data of NiTiO 3 nanocrystals were analyzed at the near-absorption edge. SEM showed that the obtained NiTiO 3 nanocrystals and NiTiO 3 /TiO 2 nanocomposite were composed of highly dispersed spherical-like and spherical particles with uniform size distribution, respectively. The chromatic properties and diffuse reflectance of samples were investigated. The obtained NiTiO 3 /TiO 2 composite samples have higher NIR reflectance than NiTiO 3 pigments.