The development of stable and reproducible inorganic pigments is noteworthy for industrial applications mainly considering more intense shades and low toxicity. Among the various candidates to substitute non‐hazardous red and yellow pigments, CeO₂ and CeO₂:Pr have been attracting attention because of their opacity and high‐temperature stability besides being environmental‐friendly and health‐friendly. In this study, nanostructured CeO₂ and CeO₂:Pr samples were synthesized using the polymeric precursor method and structural and optical characterizations were performed. Scanning electron microscopy reveals the morphology of CeO₂ nanoparticles in which the particle size ranges from 22 to 28 nm as a function of the annealing temperature. Pr‐doping does not show influence on the particle size. XRD results show that CeO₂ and CeO₂:Pr samples crystallize in the cubic fluorite lattice with Fm3m space group. Raman spectra show the fluorite F_2g mode, confirming the XRD results. With Pr‐doping and the annealing of the samples, two bands are observed between 550 and 600 cm⁻¹, which are related to the defects in the fluorite structure associated with oxygen vacancies. XPS spectra reveal an increase in the ratio of Ce³⁺ ions depending on the annealing temperature and Pr‐doping. This increase is associated with the carbon removal from the lattice by annealing. This behavior causes a change in the hue of the powders as the annealing temperature increases. According to diffuse reflectance and colorimetric measurements, CeO₂ shows a light‐yellow color due to the O 2p­Ce 4f transitions whose b* parameter mainly decreases with annealing, becoming almost white. The CeO₂:Pr sample exhibits a red‐orange color because of the electronic transitions between 4f² → 5d¹ states of Pr³⁺. Upon annealing, L* and b* parameters decrease, resulting in a red‐brown shade. The charge compensation or charge transfer is responsible for the modification of the hue of these pigments.

中文翻译：

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通过聚合前体法制备的CeO2和CeO2：Pr纳米晶体粉末：颜色可调的黄色和红色颜料

稳定和可重现的无机颜料的开发对于工业应用是值得注意的，主要是考虑到更深的色调和低毒性。在替代无害红色和黄色颜料的各种候选材料中，CeO ₂和CeO ₂：Pr除具有环保性和健康性外，还因为其不透明性和高温稳定性而备受关注。在这项研究中，使用聚合物前体方法合成了纳米结构的CeO ₂和CeO ₂：Pr样品，并进行了结构和光学表征。扫描电子显微镜揭示CeO ₂的形态纳米粒子的粒径范围为22至28 nm，这是退火温度的函数。Pr掺杂对粒度没有影响。X射线衍射结果表明CeO ₂和CeO ₂：Pr样品在Fm 3 m空间群的立方萤石晶格中结晶。拉曼光谱显示萤石F _2g模式，证实了XRD结果。通过Pr掺杂和样品退火，在550和600 cm ^-1之间观察到两个谱带，这两个谱带与氧空位有关的萤石结构缺陷有关。XPS光谱显示Ce ³⁺的比例增加离子取决于退火温度和Pr掺杂。这种增加与通过退火从晶格中除去碳有关。随着退火温度的升高，这种行为导致粉末色调的变化。根据漫反射和比色法测量，由于O 2pCe 4f跃迁，CeO ₂呈现浅黄色，其b *参数主要随着退火而降低，几乎变为白色。由于Pr ^3+的4f ²  →5d ¹状态之间的电子跃迁，CeO ₂：Pr样品呈现出橘红色。。退火后，L *和b *参数减小，导致出现红棕色阴影。电荷补偿或电荷转移负责改变这些颜料的色相。