摘要
采用水解沉淀法分别制备了未掺杂、氮掺杂和不同Ce4+浓度的氮、铈共掺杂纳米二氧化钛粉体,并利用XRD、TEM、XPS、UV-vis对其进行表征,以甲基橙的光催化降解为模型反应,考察其在太阳光下的光催化活性。结果表明,450℃下煅烧3 h制备的纳米TiO2粉体均为锐态矿型,铈的掺入使衍射峰宽化;氮、铈共掺杂能抑制锐钛矿晶粒的生长,减少团聚,使晶粒细化。N取代了TiO2晶格中的部分氧原子形成N2p掺杂能级,而铈以Ce4+、Ce3+两种价态存在于TiO2中。氮、铈的协同作用不仅使TiO2的光吸收带边红移,也能明显提高TiO2在紫外光区的吸收强度。光催化降解甲基橙实验结果表明:当Ce4+掺杂量为0.6%时,Ce-N-TiO2的光催化效率最高,约为纯二氧化钛的2倍。
Using Ti （OBu） 4 as the titanium source, the undoped, N-doped and Ce-N-eodoped TiO2 nanoparticles were prepared by hydrolysis precipitation method with ammonium eerie nitrate and ammonia as the cerium and nitrogen sources, respectively. The prepared catalysts were characterized by XRD, TEM, XPS and UV-vis. The XRD spectra showed that all samples calcined at 450℃ for 3 h were of anatase structure, the Ce doping made the peak of diffraction more wider. The results of TEM showed that the dopant N and Ce inhibited the increase of erystallite size and decreased the aggregation of TiO2 nanopartieles. The XPS analysis of Ce-N-TiO2 sample indicated that some N atoms as substitution atoms replaced for 0 atoms in TiO2 lattice, the dopant Ce existed on surface of TiO2 as Ce^4＋ and Ce^3＋. Compared with naked Ti02, Ce-N-TiO2 not only had significant optical absorption between 400 nm and 500 nm, but also enhanced the optical absorption in the UV region. The photoeatalytie activities were evaluated by monitoring the photocatalytic degradation of methyl orange on sunlight irradiation. The results indicated that 0.6% Ce-N-TiO2 had the highest photoeatalytie activity which was about 2 times as high as that of naked TiO2.
出处
《应用化工》
CAS
CSCD
2008年第8期857-860,878,共5页
Applied Chemical Industry
基金
湖南省科技厅资助项目(2007FJ4152)
关键词
TiO2
甲基橙
氮铈共掺杂
水解沉淀
光催化
titania
methyl orange
cerium and nitrogen-eodoped
hydrolysis precipitation
photoeatalytie
