模拟室内环境下掺杂TiO_2纳米晶体的光催化性能

采用环境测试舱模拟可见光下的室内环境,以甲醛气体的光催化降解为探针反应,评价了通过溶胶-凝胶法分别制备的8种（银Ag、铜Cu、铁Fe、钨W、铈Ce、镧La、硫S和氯C l）掺杂TiO2纳米晶体的光催化活性及对甲醛气体的去除效果。用X射线衍射、激光粒度分析和紫外-可见分光光谱表征了掺杂钠米TiO2的微晶尺寸、晶体结构与光学性能。结果表明,Cu掺杂可以提高TiO2对氧的吸附能力,减少纳米粒子表面光生电子与光生空穴的复合,使TiO2的光吸收带边发生红移且有利于对可见光的吸收,从而使Cu掺杂TiO2在模拟室内环境下光催化甲醛气体的能力得到明显提高。

Photocatalytic activity of doped Tio_2 nanocrystallites in simulated indoor environment

TiO2 nanocrystallite photocatalysts doped with Ag, Cu, Fe, W, Ce, La, S, Cl respectively were prepared by sol-gel method. The photocatalytic aetivites of the photocatalyst samples were determined and removal effect of formaldehyde was investigated by the photocatalytic decomposition of gas formaldehyde in the environmental chamber using a visible lamp. The characteristics of the samples were characterized by mean of X-ray diffraction ,laser particle size analyze and ultraviolet-visible diffuse reflection techniques. The effects of doping on the crystallite sizes, crystal pattern and optical properties of catalysts were investigated. The results show that doping of Cu in TiO2 nanoparticles made the ability of TiO2 particles to adsorb oxgen enhance, and decreased the recombination of photogenerated electrons and photogenerated hole in the interface of nanoparticles, cause a redshift of the onset of the absorption spectrum and enhance the visible lamp absorption ability of TiO2. The effects are responsible for the remarkable increase in potocatalytic decomposition of formaldehyde on Cu-doped TiO2 in simulated indoor environment.