Sm2O3/TiO2对亚甲基蓝染料的光催化降解行为研究

采用浸渍法制备Sm2O3掺杂TiO2的负载型光催化剂Sm2O3/TiO2,考察其在紫外可见光区对亚甲基蓝的光降解行为.利用XRD、N2吸附、SEM、TEM、XPS和ICP-OES等手段表征Sm2O3/TiO2样品,考察Sm2 O3掺杂量和亚甲基蓝浓度对亚甲基蓝紫外光降解活性的影响和催化剂Sm2O3/TiO2的催化稳定性.结果表明,Sm2O3/TiO2对亚甲基蓝的紫外光降解活性高于TiO2,这归因子掺杂Sm2O3引起TiO2的晶体缺陷.这种晶体缺陷作为光生电子和空穴的陷阱实现光生电子-空穴对的有效分离,从而提高Sm2O3/TiO2的光催化活性.Sm2O3/TiO2对亚甲基蓝的光降解活性随着Sm2O3掺杂量的增加先增大后减小,随着亚甲基蓝浓度的增大而减小.Sm2 O3掺杂量5.0wt;的Sm2O3/TiO2对亚甲基蓝紫外光降解的7次循环实验未出现明显失活.

Photocatalytic Degradation Behavior of Sm2O3/TiO2 for Methylene Blue Dye

The supported catalysts Sm2O3/TiO2,Sm2O3 doped TiO2 bulks,were synthesized by impregnation method,and employed to investigate the photodegradation behaviors of methylene blue under UV-light irradiation.The fabricated Sm2O3/TiO2 samples were characterized by several techniques such as XRD、SEM、TEM、N2-adsorption,XPS,ICP-OES.The effects of experiential parameters such as Sm2O3 content and methylene blue concentration on the photocatalytic degradation performance in methylene blue as well as photocatalytic stability were also performed.The results show that Sm2O3/TiO2 exhibited higher photocatalytic activity for methylene blue compared with TiO2-alone under UV-light region,which is ascribed to the crystal defect of TiO2 generated by Sm2O3 doping.This crystal effect,as the trap of photo electrons and holes,can achieve the effective separation of electron-hole pairs,landing to the enhancement in photocatalytic activity of Sm2O3/TiO2 samples.The photodegradation activity of Sm2O3/TiO2 increases and then decreases as Sm2O3-doped content increasing,while decreased with methylene blue concentration.Sm2O3/TiO2 samples with Sm2O3-doped content of 5.0wt％ did not exhibit an evident loss of activity for the UV-light droved degradation of methylene blue after seven cycles under the same conditions.