Non-toxic rare earth (RE) composite materials are promising and active in optoelectronic fields, such as pigment. In this work, Na ions doped γ-Ce₂S₃ pigments were synthesized by solid-phase vulcanization and followed by in-situ synthesis to prepare an outer layer of CePO₄ film. The characterizations of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), solid state nuclear magnetic resonance (NMR) indicate that Na-doped γ-Ce₂S₃ and CePO₄ uniformly and tightly coated core–shell structure was successfully synthesized. The thermogravimetric analysis (TG) and reflection spectrum (RS) reveal that the CePO₄ coating significantly improves the colorant and thermal stability performance of γ-Ce₂S₃. The excellent color quality of γ-Ce₂S₃@CePO₄ (L∗ = 45.16, a∗ = 55.94, b∗ = 44.53) is achieved and the red color (L∗ = 43.82, a∗ = 49.79, b∗ = 38.04) is still retained even if the sample is heated in air at 400 °C for 30 min.

无毒稀土（RE）复合材料在颜料等光电领域具有广阔的应用前景和活跃性。本工作采用固相硫化法合成Na离子掺杂的γ-Ce ₂ S _{3颜料，然后}原位合成制备CePO ₄薄膜外层。X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)、固态核磁共振(NMR)的表征表明Na掺杂的γ-Ce ₂ S ₃和 CePO ₄成功合成了均匀且紧密包覆的核壳结构。热重分析（TG）和反射光谱（RS）表明，CePO ₄涂层显着提高了γ-Ce ₂ S ₃的着色剂和热稳定性能。_{实现了 γ-Ce 2} S ₃ @CePO ₄ ( L∗  = 45.16, a∗  = 55.94, b∗ = 44.53)的优异色彩质量 和红色 ( L∗  = 43.82, a∗  = 49.79, b∗  =即使样品在 400 °C 的空气中加热 30 分钟，仍然保留 38.04)。