Synthesis and coloration of highly dispersed NiTiO3@TiO2 yellow pigments with core-shell structure

The highly dispersed NiTiO3@TiO2 yellow pigments with core-shell structure were prepared through calcinations of precursors obtained from the precipitation of Ni2+ on the surface of TiO2 particles. The synthesized pigments were characterized by XRD, SEM, TEM, Uv-vis spectroscopy and colorimetry. The pigments were found to consist of TiO2 core and outer ilmenite NiTiO3 shell. The optical absorption of Ni2+ in octahedral coordination produced intense yellow colors. Compared with pure NiTiO3, the NiTiO3@TiO2 pigments presented higher yellow and lower red hues, resulted in intense yellow colors. The particle size distribution of the prepared pigments and ζ potential measurement indicated that the NiTiO3-0.75@TiO2 pigments were uniform and well-dispersed in glycol solvents, and they form relatively more stable suspension than pure NiTiO3 pigments. Meanwhile, these pigments were stable in commercial low-temperature ceramic glazes, possessed more brilliant yellowish colors than pure NiTiO3 prepared by sol-gel method.