La3+-Pr3+共掺杂纳米TiO2粉体的光催化性能

以钛酸四丁酯(TBT)为原料, 采用溶胶-凝胶法制备了纯TiO₂和La³⁺-Pr³⁺共掺杂复合粉体(La³⁺-Pr³⁺/TiO₂), 采用XRD、 UV-Vis和TEM等测试手段分析了在紫外光照射下, 以降解甲基橙为探针反应研究其可见光催化性能。结果显示: 所有样品均为锐钛矿相纳米TiO₂, 稀土元素镧和镨掺杂后TiO₂特征衍射峰宽化, 强度降低; 与纯TiO₂、 镧掺杂TiO₂与镨掺杂TiO₂相比, 光催化剂La³⁺-Pr³⁺共掺杂TiO₂颗粒的粒径更小, 比表面积更大, 光吸收边红移程度更显著; 与未掺杂和单一掺杂的TiO₂相比较, 共掺杂的TiO₂具有更高的可见光催化性能。当La³⁺与TiO₂和Pr³⁺与TiO₂的摩尔比分别为1.0%和0.2%时, 可见光催化性能最好。可见光催化性能的提高归因于镧和镨的协同作用。

Influence of La^3+ and Pr^3+ co-doped on photocatalytic properties of TiO2 nanoparticles

Pure nano TiO₂ and La³⁺-Pr³⁺ co-doped nano-TiO₂(La³⁺-Pr³⁺/TiO₂) catalyst were prepared by a sol-gel method with TBT and distilled water as forerunner body, ethanol as solvent and glacial acetic acid as inhibitor. The prepared samples were characterized by XRD, TEM and UV-Vis. The UV-light photocatalytic performance of the obtained materials was evaluated by methylene orange decomposition. The results show that the prepared samples are all pure anatase phase nano-TiO₂ and their diffraction peak broadens obviously after La³⁺-Pr³⁺ co-doped. Compared with pure TiO₂, the particle sizes of La³⁺-Pr³⁺ co-doped TiO₂ are smaller, its specific surface area is larger, and its absorption edge shifts more remarkably towards longer wavelength. The photocatalytic activity of La³⁺-Pr³⁺ co-doped TiO₂ is higher than that of TiO₂ or La³⁺(Pr³⁺)-doped TiO₂, which is enhanced with the La³⁺ and Pr³⁺ contents, reaching the maximum at the La³⁺/TiO₂ and Pr³⁺/TiO₂ molar ratios of 1.0% and 0.2%, respectively. The enhanced visible photocatalytic performance is attributed to the synergetic effect of La³⁺ and Pr³⁺ co-doped.