Lanthanum doped TiO2 nanoparticles (La doped TiO2) have been prepared by a sol-gel process using TiO(C4H9)4 as raw material and are characterized using XRD, FT-IR, SEM-EDS, TEM and UV-DRS. The insertion of La ion in TiO2 lattice has been confirmed by SEM-EDS and XRD data. TEM studies have confirmed that La ions are uniformly doped over TiO2 lattice. The band gap level of La doped TiO2 is decreased to 2.92 eV with a red shift due to charge transfer reaction which is confirmed by UV-DRS. The photocatalytic activities of the synthesized nanoparticles are evaluated for the degradation of Congo red dye (20 ppm) in an aqueous solution with La doped TiO2 (0.25 g) at pH= 6.3, under solar light irradiation. The photocatalytic results confirmed that the La doped TiO2 show good photocatalytic activity and can be considered as a promising photocatalyst for the degradation of organic pollutants in water. Due to the stability of La doped TiO2 nanoparticles, it could be reused for more than five cycles reaching 100% degradation efficiency.

中文翻译：

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稀土金属掺杂二氧化钛在可见光照射下增强光催化降解偶氮染料

以TiO(C4H9)4为原料，采用溶胶-凝胶法制备了镧掺杂二氧化钛纳米粒子（La掺杂二氧化钛），并采用XRD、FT-IR、SEM-EDS、TEM和UV-DRS对其进行了表征。SEM-EDS 和 XRD 数据证实了 La 离子在 TiO2 晶格中的插入。TEM 研究证实，La 离子均匀地掺杂在 TiO2 晶格上。由于UV-DRS证实的电荷转移反应，La掺杂的TiO2的带隙水平降低到2.92 eV并出现红移。合成纳米粒子的光催化活性在太阳光照射下，在 pH=6.3 的 La 掺杂 TiO2 (0.25 g) 水溶液中对刚果红染料 (20 ppm) 的降解进行了评估。光催化结果证实，La掺杂的TiO2表现出良好的光催化活性，可以被认为是一种很有前途的光催化剂，用于降解水中的有机污染物。由于 La 掺杂的 TiO2 纳米粒子的稳定性，它可以重复使用超过 5 个循环，达到 100% 的降解效率。