Benefitting from a suitable band gap, ceria is an excellent material for UV shielding. By solid solution doping and specific micromorphology, its band gap can be effectively controlled. In this paper, ceria doped with lanthanum via oxalate precipitation is combined with a high-temperature roasting process. The properties of the prepared samples are characterized by UV–Vis diffuse reflectance spectroscopy (DRS), Raman, XRD, FESEM and XPS. The absorption threshold of materials is clearly red-shifted in the ultraviolet band, which originates from the electron-phonon generation. To further reveal the mechanism, the density function theory calculation (DFT) is implemented to study the influence of lanthanum concentrations on ceria’s band gap. It is demonstrated that the band gap can even be narrowed to 2.97 eV by optimizing the sintering temperature and lanthanum-doped concentration. To investigate its improved anti-aging properties under ultraviolet rays, different amounts of 5% lanthanum-doped ceria is mixed with an Al-based coating and then coated on the Q235 steel. Combined with an ultraviolet light irradiation experiment and electrochemical test technology, the corrosion resistance of the modified coatings is evaluated. The coating with 20% La-doped ceria provides the best corrosion resistance performance.

中文翻译：

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La-Doped CeO2 粉末协同改进涂层的抗紫外线老化和防腐性能

得益于合适的带隙，氧化铈是一种极好的紫外线屏蔽材料。通过固溶掺杂和特定的微观形貌，可以有效控制其带隙。在本文中，通过草酸盐沉淀掺杂镧的氧化铈与高温焙烧工艺相结合。制备的样品的性质通过紫外-可见漫反射光谱（DRS）、拉曼、XRD、FESEM 和 XPS 表征。材料的吸收阈值在紫外波段明显发生红移，这源于电子-声子的产生。为了进一步揭示该机制，实施密度函数理论计算（DFT）来研究镧浓度对氧化铈带隙的影响。结果表明，带隙甚至可以缩小到 2。通过优化烧结温度和镧掺杂浓度达到 97 eV。为了研究其在紫外线下改善的抗老化性能，将不同量的 5% 掺镧氧化铈与铝基涂层混合，然后涂覆在 Q235 钢上。结合紫外光照射实验和电化学测试技术，对改性涂层的耐腐蚀性能进行了评价。含 20% La 掺杂氧化铈的涂层提供了最佳的耐腐蚀性能。评估了改性涂层的耐腐蚀性。含 20% La 掺杂氧化铈的涂层提供了最佳的耐腐蚀性能。评估了改性涂层的耐腐蚀性。含 20% La 掺杂氧化铈的涂层提供了最佳的耐腐蚀性能。