Tb^(3+)和Sm^(3+)共掺杂对TiO_2降解亚甲基蓝的影响

EFFECT OF Tb^(3+) AND Sm^(3+) CO-DOPED ON THE PHOTOCATALYTIC DEGRADATION OF METHYLENE BLUE BY TiO_2

采用溶胶-凝胶法制备纯TiO2和Tb3+/Sm3+共掺杂TiO2复合粉体,采用XRD、DRS和SEM等技术进行表征,以亚甲基蓝(methylene blue,MB)的光催化降解为目标反应,评价其光催化活性,探讨Tb3+/Sm3+共掺杂对TiO2光催化性能的影响机制。结果表明,Tb3+/Sm3+共掺杂可显著提高TiO2光催化活性,Tb3+/Sm3+共掺杂在TiO2中产生协同作用,可抑制TiO2由锐钛矿相向金红石相转变,使TiO2粒径减小。Tb3+/Sm3+共掺杂增大了TiO2的晶格畸变,使TiO2吸收带边蓝移。当Tb3+/Sm3+的掺杂量分别为0.1%和0.2%时,TiO2光催化活性最高,降解率达到91.46%。

Pure TiO2, Tb3＋ and Sm3＋ co-doped TiO2 composite nano-particle were prepared by sol-gel method and characterized by the techniques such as XRD, DRS and SEM. The photocatalytic degradation of methylene blue （MB） in aqueous solution was used as a probe reaction to evaluate their photocatalytic activity. The mechanisms of effects of Tb3 ＋ and Sm3 ＋ co-doped on the photocatalytie activity of the TiO2 composite nano-particles were also discussed. The results showed that Tb3＋ and Sm3＋ co-doped can significantly enhance the photocatalytic activity of TiO2 nano-particles. The co-doped of Tb3 ＋ and Sm3 ＋ showed a synergistic effect for photocatalytic activity of TiO2 nano-particles, can inhibt the phase transformation from anatase to rutile and decrease the diameter of TiO2 nanoparticles. The matrix distortion of TiO2 nano-particles increases when the Tb3＋ and Sm3＋ have co-doped and the blue-shift of the absorption profile were clearly observed. When the co-doped amounts for Tb3 ＋ and Sm3 ＋ were 0. 1% and 0.2%, the photocatalytic activity of TiO2 can be improved sffeetively, and its degradation rate reached 91.46%.