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 dis...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.展开更多
Various affecting factors and degradation mechanism were studied on ultrasonic degradation of methyl orange adopting Y2O3 doping anatase TiO2 catalyst prepared in laboratory.In the experiment, the UV-VIS spectrophotom...Various affecting factors and degradation mechanism were studied on ultrasonic degradation of methyl orange adopting Y2O3 doping anatase TiO2 catalyst prepared in laboratory.In the experiment, the UV-VIS spectrophotometer was used to follow and inspect the degradation process of methyl orange.The results indicate that the ultrasonic degradation ratios of methyl orange in the presence of anatase TiO2 catalyst are much better than those without catalyst.Moreover, the catalytic performance of Y2O3 doping anatase TiO2 catalyst is obviously higher than that of anatase TiO2 catalyst without doping.The optimal conditions were adopted in this work and the degradation and COD elimination ratio of methyl orange got to98% and 99.0% in 90 min, respectively.展开更多
TiO2/（O＇ ＋ β＇）-Sialon multiphase ceramics were prepared with nano TiO2 （anatase） powder and （O＇ ＋ β＇）-Sialon powder as raw materials. Effect of Yb2O3 additive on transformation behavior of anatase for Ti...TiO2/（O＇ ＋ β＇）-Sialon multiphase ceramics were prepared with nano TiO2 （anatase） powder and （O＇ ＋ β＇）-Sialon powder as raw materials. Effect of Yb2O3 additive on transformation behavior of anatase for TiO2/（O＇ ＋ β＇）-Sialon multi phase ceramic was investigated and its influence mechanism was discussed. XRD was employed for the analysis of phase composition and lattice parameters. The results show that even though Yb2O3 has no obvious influence on starting temperature of phase transformation, it significantly accelerates the transformation process, which displays a weakened effect with more Yb2O3 addition. There exist two forms of the added Yb2O3 ： some enters TiO2 lattice and the other deposits on the surface of TiO2. The function of Yb2O3 on phase transformation of anatase can be attributed to the coaction of active and negative influence mechanisms as follows： some Yb^n＋ enter TiO2 lattice and replace Ti^4＋ , as well as the redox reaction between Yb^3＋ and TiO2, which promote the transformation, whereas other Yb2O3 deposits on the surface of TiO2, and Ti- O-Yb bond is formed by the coaction of Yb^3＋ and TiO2, which inhibit the process.展开更多
基金supported by the National Natural Science Foundation of China (50202004)
文摘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.
基金Project supported by the National Natural Science Foundation of China(20371023 )
文摘Various affecting factors and degradation mechanism were studied on ultrasonic degradation of methyl orange adopting Y2O3 doping anatase TiO2 catalyst prepared in laboratory.In the experiment, the UV-VIS spectrophotometer was used to follow and inspect the degradation process of methyl orange.The results indicate that the ultrasonic degradation ratios of methyl orange in the presence of anatase TiO2 catalyst are much better than those without catalyst.Moreover, the catalytic performance of Y2O3 doping anatase TiO2 catalyst is obviously higher than that of anatase TiO2 catalyst without doping.The optimal conditions were adopted in this work and the degradation and COD elimination ratio of methyl orange got to98% and 99.0% in 90 min, respectively.
文摘TiO2/（O＇ ＋ β＇）-Sialon multiphase ceramics were prepared with nano TiO2 （anatase） powder and （O＇ ＋ β＇）-Sialon powder as raw materials. Effect of Yb2O3 additive on transformation behavior of anatase for TiO2/（O＇ ＋ β＇）-Sialon multi phase ceramic was investigated and its influence mechanism was discussed. XRD was employed for the analysis of phase composition and lattice parameters. The results show that even though Yb2O3 has no obvious influence on starting temperature of phase transformation, it significantly accelerates the transformation process, which displays a weakened effect with more Yb2O3 addition. There exist two forms of the added Yb2O3 ： some enters TiO2 lattice and the other deposits on the surface of TiO2. The function of Yb2O3 on phase transformation of anatase can be attributed to the coaction of active and negative influence mechanisms as follows： some Yb^n＋ enter TiO2 lattice and replace Ti^4＋ , as well as the redox reaction between Yb^3＋ and TiO2, which promote the transformation, whereas other Yb2O3 deposits on the surface of TiO2, and Ti- O-Yb bond is formed by the coaction of Yb^3＋ and TiO2, which inhibit the process.
基金National Natural Science Foundation of China(51702171,51872286,51832007)Zhejiang Provincial Qianjiang Talent Program of China(QJD1702017)+2 种基金Natural Science Foundation of Ningbo(2019A610052)Key Laboratory of Optoelectronic Materials Chemistry and Physics,Chinese Academy of Sciences(2008DP173016)Science and Technology Plan Leading Project of Fujian Province(2018H0046)。
