Ca2+离子掺杂对γ-Ce2S3合成温度及热稳定性的影响

以CeCl₃·7H₂O、CaCl₂·2H₂O和C₂H₂O₄·2H₂O为原料,在制备钙铈氧化物前驱体基础上,再以Ar气为载气、CS₂为硫源对钙铈氧化物前驱体进行硫化合成Ca²⁺掺杂的γ-Ce₂S₃色料。 通过X射线衍射(XRD)、紫外-可见漫反射光谱(UV-Vis)及差热-热重分析(TG-DTA)等技术手段表征了色料的结构和性能。 结果表明,Ca²⁺掺杂能够明显降低γ-Ce₂S₃的合成温度,当n(Ca²⁺):n(Ce³⁺)≥0.16时,在900 ℃硫化150 min即可获得纯相的γ-Ce₂S₃,与不掺杂时合成γ-Ce₂S₃的温度相比降低了300 ℃左右。 同时,Ca²⁺掺杂能够提升γ-Ce₂S₃的抗氧化能力,当n(Ca²⁺):n(Ce³⁺)=0.64时,氧化放热峰的温度由不掺杂时的490.6 ℃提高至541.0 ℃。

Effect of Ca2+-Doping on Synthesis Temperature and Heat Stability of γ-Ce2S3

CeCl₃·7H₂O, CaCl₂·2H₂O and C₂H₂O₄·2H₂O were used as raw materials to prepare Ca²⁺-doped cerium oxalate by the coprecipitation method. The Ca²⁺-doped cerium oxalate was calcined to obtain Ca²⁺-doped cerium oxide precursor. Ca²⁺-doped γ-Ce₂S₃ was achieved by vulcanizing precursors in an Ar atmosphere using CS₂ as the sulfur source. Pigments were characterized by X-ray diffraction(XRD), energy dispersive spectrometer(EDS), color analyzer, UV-Vis spectrophotometer and thermogravimetric analysis-differential thermal analysis(TG-DTA). The results show that Ca²⁺-doping can lower the synthesis temperature and improve the thermal stability of pigments in air. When the ratio of n(Ca²⁺):n(Ce³⁺)≥0.16, pure phase γ-Ce₂S₃ can be obtained by vulcanizing at 900 ℃ for 150 min. The synthesis temperature of doped γ-Ce₂S₃ decrease by 300 ℃ compared with undoped γ-Ce₂S₃. When the n(Ca²⁺):n(Ce³⁺) is 0.64, the oxidation exothermic peak of Ca²⁺-doped γ-Ce₂S₃ increases from 490.6 to 541.0 ℃.