摘要
讨论了TiO2光催化技术研究现状、探讨了光催化反应机制,分析了提高光催化反应活性的途径,并讨论了影响纳米TiO2光催化活性的主要因素:一般而言,锐钛矿型TiO2的光催化活性高于金红石型TiO2;晶粒尺寸小,光生电子和空穴从TiO2体内扩散到表面的时间短,它们在TiO2体内的复合几率减小,光催化活性高;贵金属沉积可提高催化剂表面光生载流子的分离效率,有利于生成更多的.OH;半导体耦合可提高系统的电荷分离效果,扩展对光谱吸收范围;金属离子掺入TiO2晶格中可能引起晶格位置缺陷或改变结晶度,抑制电子与空穴的复合,延长载流子的寿命,从而使光催化性能得以改善;TiO2表面羟基的数量直接影响光催化效率。
The present advance of photocatalytic technology and the mechanism of photocatalytic reaction were described. The approaches improving the photocatalytic activity of TiO2 were analysed. These primary factors affecting the photocatalytic activity of nanoTiO2 were discussed： Under the general conditions, the photocatalytic activity of anatase-type TiO2 is higher than one of rutile-type TiO2. The smaller diameters of crystal particles of TiO2 are, the shorter the time which the electrons （e-） and the holes （h ＋ ） of light stimulating spread to the surface of TiO2 from the interior of TiO2 is, and the probability of e^- and h ＋ combining reduces, which improves the photocatalytic activity of TiO2. Depositing of noble metals can promote separating efficiency of current carriers on the surface of TiO2, which is beneficial to form more · OH. Coupling of semiconductors can improve separating results of charges of system and expand the absorption spectrum of TiO2. Metal ions doped enter into the crystal lattices of TiO2 to cause the defect of crystal lattices of TiO2, which restrains e^- and h＋ to combine, delays the life-span of current carriers, and improves the photocatalytic activity of TiO2. Amounts of hydroxyl on the surface of TiO2 directly influence photocatalytic efficiency.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2006年第1期107-113,共7页
Chinese Journal of Rare Metals
基金
安徽省自然科学基金(050450301)资助项目
安徽省"十五"优秀人才-安徽省高校中青年学科带头人培养对象计划经费资助
阜阳师范学院配套经费资助项目
关键词
光催化技术
纳米材料
晶型
二氧化钛
photoeatalytie technology
nanometer material
crystal types
titanium dioxide
