Effect of Tb_2O_3 additive on structure of anatase and photocatalytic activity of TiO_2/(O'+β')-Sialon multi-phase ceramics  

作　　者：杨建 潘丽梅 薛向欣 王梅 丘泰 

机构地区：[1]College of Materials Science and Engineering,Nanjing University of Technology,Nanjing 210009,China [2]School of Materials and Metallurgy,Northeastern University,Shenyang 110004,China

出　　处：《Journal of Rare Earths》2009年第2期204-210,共7页稀土学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (50202004)

摘　　要：Effect of rare earth oxide Tb2O3 additive on transformation behavior and grain growth of anatase and photocatalytic activity for TiO2/（O′＋β′）-Sialon multi-phase ceramic was investigated and the mechanism was discussed. X-ray diffractometer （XRD） was employed for the analysis of phase composition, grain size and lattice parameters of anatase. Photocatalytic activity of the composites was investigated through its photocatalytic degradation to methylene blue （MB） solution. The results showed that Tb2O3 significantly inhibited the transformarion process, which displayed an appreciably intensified effect with increasing Tb2O3 content. It could be attributed to the coaction of the active and passive influence mechanisms. For Tb3＋ entering TiO2 lattice, replacing Ti4＋ accelerated the transformation, whereas the lattice distortion caused by it was unfavorable for the process. On the other hand, the redox reaction between Tb3＋ and TiO2 as well as the Tb2O3 deposited on the surface of TiO2 inhibited the transformation. The addition of Tb2O3 effectively restrained the grain growth of TiO2 and the effect became significant with the increase of its content. With the increase of Tb2O3 addition, the photocatalytic activity of the catalysts increased and then dropped after reaching the maximum at about 2%. The action mechanism of Tb2O3 could be attributed to its optical properties and its effect on phase transformation, grain growth and crystal structure of TiO2.Effect of rare earth oxide Tb2O3 additive on transformation behavior and grain growth of anatase and photocatalytic activity for TiO2/（O′＋β′）-Sialon multi-phase ceramic was investigated and the mechanism was discussed. X-ray diffractometer （XRD） was employed for the analysis of phase composition, grain size and lattice parameters of anatase. Photocatalytic activity of the composites was investigated through its photocatalytic degradation to methylene blue （MB） solution. The results showed that Tb2O3 significantly inhibited the transformarion process, which displayed an appreciably intensified effect with increasing Tb2O3 content. It could be attributed to the coaction of the active and passive influence mechanisms. For Tb3＋ entering TiO2 lattice, replacing Ti4＋ accelerated the transformation, whereas the lattice distortion caused by it was unfavorable for the process. On the other hand, the redox reaction between Tb3＋ and TiO2 as well as the Tb2O3 deposited on the surface of TiO2 inhibited the transformation. The addition of Tb2O3 effectively restrained the grain growth of TiO2 and the effect became significant with the increase of its content. With the increase of Tb2O3 addition, the photocatalytic activity of the catalysts increased and then dropped after reaching the maximum at about 2%. The action mechanism of Tb2O3 could be attributed to its optical properties and its effect on phase transformation, grain growth and crystal structure of TiO2.

关 键 词：anatase  Tb2O3 phase transformation grain growth photocatalytic activity mechanism rare earths 

分 类 号：TQ174.6[化学工程—陶瓷工业]