The TiO₂@CoAl₂O₄ complex blue pigments with low cobalt content were synthesized through calcinations of the precursor obtained from coprecipitating Co²⁺ and Al³⁺ to form Co‐Al LDHs (layered double hydroxides) on the surface of TiO₂ particles. The structure and the properties of the synthesized pigments were characterized by XRD, SEM, TEM, UV‐Vis spectroscopy, XPS, and colorimeter. The precursors of the blue TiO₂@CoAl₂O₄ complex pigments were consisted of LDHs shell layer encapsulated TiO₂ microsphere. After calcinations at 1100°C, the LDHs shell layer were absolutely transformed to the spinel CoAl₂O₄, and the pigments presented a core‐shell structure and uniform sphere morphology (the diameter of microsphere was about 780 nm). The absorption bands at around 547, 584, and 624 nm in the Uv‐Vis absorption spectra of the TiO₂@CoAl₂O₄ complex pigments were corresponded to the characteristic absorption bands of the spinel CoAl₂O₄, revealed the pigments with a bright blue hue. In addition, as the mass ratio of CoAl₂O₄/TiO₂ increased to 0.4, the blue component of the pigments reached to 27.89 and slight color variation with the increase in the CoAl₂O₄ content in a range, possessed low cobalt content and exhibited a stabile performance in commercial low‐temperature ceramic glazes. The XGT results showed that the TiO₂@CoAl₂O₄ complex pigments with low cobalt content presented bright color in ceramic glaze. Especially, the synthesized pigments reduced the usage and toxicity of cobalt, which were efficiency for economy and environmental protection.

中文翻译：

---

低钴含量的TiO2 @ CoAl2O4蓝色颜料在陶瓷釉料中的合成及颜色特性

通过煅烧从Co ²⁺和Al ³⁺共沉淀而在TiO ₂颗粒表面形成Co-Al LDHs（层状双氢氧化物）得到的前驱体，合成了低钴含量的TiO ₂ @CoAl ₂ O ₄复合蓝色颜料。。通过XRD，SEM，TEM，UV-Vis光谱，XPS和色度计对合成颜料的结构和性能进行了表征。蓝色TiO ₂ @CoAl ₂ O ₄复合颜料的前体由LDHs壳层包裹的TiO _2组成微球。在1100°C下煅烧后，LDHs的壳层完全转变为尖晶石CoAl ₂ O ₄，颜料呈现出核-壳结构和均匀的球形形态（微球的直径约为780 nm）。TiO ₂ @CoAl ₂ O ₄复合颜料在Uv-Vis吸收光谱中在547、584和624 nm附近的吸收带与尖晶石CoAl ₂ O ₄的特征吸收带相对应，显示出具有明亮的蓝色调。另外，作为CoAl ₂ O ₄ / TiO ₂的质量比，增加到0.4，颜料的蓝色成分达到27.89，并且随着一定范围内CoAl ₂ O ₄含量的增加，颜色略有变化，钴含量低，并且在商业低温陶瓷釉料中表现出稳定的性能。XGT结果表明，低钴含量的TiO ₂ @CoAl ₂ O ₄复合颜料在陶瓷釉中呈现亮色。特别是，合成的颜料减少了钴的使用和毒性，这对于经济和环境保护是有效的。