掺杂镧的TiO_2纳米粒子的光致发光及其光催化性能  

Photoluminescence of Lanthanum-Doped TiO_2 Nanoparticles and Their Photocatalytic Activity

作　　者：井立强[1] 张新[1] 屈宜春[1] 孙志华[1] 李姝丹[1] 蒋保江[1] 付宏刚[1] 孙家钟[2] 

机构地区：[1]黑龙江大学化学化工与材料学院物理化学实验室,黑龙江哈尔滨150080 [2]吉林大学理论化学研究所理论化学与计算国家重点实验室,吉林长春130023

出　　处：《中国稀土学报》2004年第6期746-750,共5页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金(20171016;20301006);黑龙江省自然科学基金(B0305);黑龙江省教育厅骨干教师创新能力资助计划(1054G035);黑龙江大学2003年度校杰出青年基金资助项目;中国博士后科学基金(20040350168)

摘　　要：采用溶胶 凝胶法制备了纯的和掺杂La的TiO2纳米粒子,并利用XRD,TEM,XPS和荧光光谱(FS)等对样品进行表征,主要考察焙烧温度和La含量对TiO2纳米粒子的性质以及光催化降解苯酚活性的影响,并探讨了La的掺杂对TiO2相变的作用机制以及FS光谱与光催化活性的关系。结果表明,适量La掺杂能够提高TiO2纳米粒子FS光谱强度,这是因为La掺杂能够使表面氧空位和缺陷的浓度增加;600℃热处理的掺杂不同量La的TiO2样品的光催化活性顺序是:1%>1.5%>3%>0.5%>5%>0%,这与它们的FS光谱强度的顺序是一致的,即FS光谱强度越高,其光催化活性越高。这是因为在光致发光过程中,FS信号主要来源于表面氧空位和缺陷,而在光催化反应过程中,表面氧空位和缺陷能够有利于光生电子被捕获。Pure and La-doped TiO_2　nanoparticles were prepared by a sol-gel process, and also were characterized by XRD, TEM, XPS and FS spectra. The effects of calcining temperature and La content on the properties and the photocatalytic activity for degrading phenol of TiO_2　nanoparticles were investigated, and the relationships between FS spectra and photocatalytic activity as well as the effect mechanisms of La-doped on TiO_2 phase change were also discussed. The results show that La dopant can improve the intensity of FS spectra with an appropriate content, which is attributed to the increase in the content of surface oxygen vacancies and defects. The orders of the photocatalytic activity of different content of La-doped TiO_2 nanoparticles calcined at 600 ℃ are as follows: 1%>1.5%>3%>0.5%>5%>0%, which is in good agreement with the orders of their FS intensity, namely, the higher the FS intensity, the higher the photocatalytic activity. This can be explained by the points that FS spectra mainly result from surface oxygen vacancies and deffects during the process of photoluminescence, while surface oxygen vacancies and deffects can easily capture or bind the photo-induced electrons during the process of photocatalytic reaction.

关 键 词：光催化 TIO2 纳米粒子 掺杂 镧 光致发光 稀土 

分 类 号：O643.3[理学—物理化学]