第 40 卷第 4 期 中南大学学报(自然科学版) Vo l . 4 0 No.4
2009 年 8 月 Journal of Central South University (Science and Technology) Aug. 2009
具有可见光光催化活性 N 掺杂纳米二氧化钛的制备和表征
彭 兵,刘立强,齐萨仁,柴立元,刘云超,李国良
(中南大学 冶金科学与工程学院,湖南 长沙,410083)
摘 要:以廉价的 TiOSO
4
为原料,通过水解法制备正钛酸前驱体,然后,向正钛酸前驱体中加入尿素作为氮源,
经煅烧制备氮掺杂纳米二氧化钛。用 X 射线衍射、紫外−可见吸收光谱、热重−差热分析和 X 射线光电子能谱等
方法对制备的样品进行表征,考察煅烧温度、煅烧时间及 Ti 与 N 配比等对光催化活性的影响。研究结果表明:
制备的样品均为锐钛矿,氮掺杂使二氧化钛在可见光区的光吸收明显增强;煅烧温度和 Ti 与 N 配比对光催化性
能影响显著;于 400 ℃制备的样品中存在 1 个最佳的 Ti 与 N 配比,所对应的可见光催化活性最强,甲基橙降解
实验 15 min 时脱色率达到 97%。
关键词:硫酸氧钛;氮掺杂 TiO
2
;尿素;可见光;光催化
中图分类号:TQ134.11 文献标识码:A 文章编号:1672−7207(2009)04−0944−06
Preparation and characterization of N-doped TiO
2
nano-powder with visible light photocatalytic activity
PENG Bing, LIU Li-qiang, QI Sa-ren, CHAI Li-yuan, LIU Yun-chao, LI Guo-liang
(School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China)
Abstract: The nano-meter particle of TiO
2
precursor was prepared by hydrolysis with industrial titanic solution, and then
urea was added as the source of nitrogen. The mixture was calcined to obtain N-doped TiO
2
. The prepared samples were
then characterized using X-ray diffractrometry, UV-Vis absorption spectra, TG-DTA and X-ray photoelectron
spectroscopy. The effects of calcination temperature, time and mole ratio of Ti to N on the photocatalytic activity were
investigated. The results show that all catalysts are anatase, and the doping of nitrogen leads to an obvious increase in
optical absorption intensity in the visible-light region. The calcination temperature and mole ratio of Ti to N has
significant influence on photoctalytic activity. There exists an optimal mole ratio of Ti to N for the catalysts calcined at
400 ℃, which results in the highest visible-light photoctalytic activity. In the experiment of degradation of methyl orange,
the degradation rate reaches 97% in 15 min.
Key words: industrial titanium sulphate solution; N-doped TiO
2
; urea; visible light; photocatalysis
自从 1972 年 Fujishima 等
[1]
发现 TiO
2
单晶电极在
光的作用下可分解水以来,人们就致力于对半导体材
料光催化技术的研究
[2]
。二氧化钛以其成本低、化学
稳定性强、安全无毒、无二次污染等优点成为光催化
领域研究的热点。但是,目前困扰二氧化钛光催化剂
的应用有两大难题:一是由于二氧化钛的禁带较宽
(E
g
=3.2 eV),只能响应波长在 387.5 nm 以下的紫外光
(约占太阳能 8% ),而太阳光谱中占绝大多数的可见光
(能量约占 45%)则未能被有效利用
[3]
;二是纳米 TiO
2
的光生电子和空穴容易复合,导致光量子效率很
低。因此,缩小催化剂的禁带宽度使吸收光谱向可见
光扩展及抑制光生电子与空穴的复合成为目前研究的
收稿日期:2008−10−04;修回日期:2008−12−22
基金项目:湖南省科技厅科技计划项目(2007CK3075)
通信作者:彭 兵(1956−),男,湖南汩罗人,教授,从事冶金环境工程与环境材料研究;电话: 0731-88830875; E-mail: Pb@mail.csu.edu.cn