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利用溶胶-溶剂热技术制备了锐钛矿型Yb掺杂和未掺杂TiO2纳米粒子,以亚甲基蓝(MB)溶液在紫外光和可见光照射下的光催化脱色率评价其光活性,考察了溶剂热温度、Yb掺杂量和焙烧温度对样品光活性的影响;结合XRD,BET,XPS,FT-IR,DRS和PL表征手段,探讨了Yb掺杂对TiO2光活性的影响机制。结果表明,低量Yb掺杂不仅显著提高TiO2的紫外光活性,也明显提高其可见光活性。Yb掺杂调整TiO2带隙内部电子分布状态,有效抑制光生e-/h+复合,提高量子效率;并且增加表面羟基,增大比表面积,改善表面织构特性,致使紫外光活性提高。然而Yb掺杂并未引起紫外吸收带边红移,其可见光活性的提高应归因于Yb掺杂强化了表面吸附染料的敏化作用。
The anatase Yb-doped and undoped TiO2 nanoparticles were prepared by sol-solvothermal technique. The photocatalytic decolorization rate of methylene blue (MB) solution under ultraviolet light and visible light irradiation was evaluated. The effects of solvent heat The effect of Yb doping on the photocatalytic activity of TiO2 was investigated by XRD, BET, XPS, FT-IR, DRS and PL techniques. The results show that the low amount of Yb doping not only significantly enhance the UV activity of TiO2, but also significantly improve the visible light activity. Yb doping adjusts the internal electron distribution in the band gap of TiO2 to effectively inhibit the recombination of photogenerated e- / h + and improve the quantum efficiency; and increases the surface hydroxyl group, increases the specific surface area and improves the surface texture properties, thereby increasing the UV activity. However, Yb doping did not cause red shift along the UV band edge. The increase of visible light activity should be attributed to the sensitization of surface-adsorbed dye by Yb doping.