Institut für Technische Chemie, Leibniz Universität Hannover, Callinstr. 3, 30167 Hannover, Germany.
J Hazard Mater. 2012 Apr 15;211-212:240-6. doi: 10.1016/j.jhazmat.2011.11.041. Epub 2011 Nov 22.
Air pollution by nitrogen oxides represents a serious environmental problem in urban areas where numerous sources of these pollutants are concentrated. One approach to reduce the concentration of these air pollutants is the light-induced oxidation in the presence of molecular oxygen and a photocatalytically active building material, e.g., paints, roof tiles, or pavement stones. Herein, results of an investigation concerning the photocatalytic oxidation of nitrogen(II) oxide (NO) in the presence of molecular oxygen and UV(A) irradiated TiO(2) powder are presented. The standard operating procedure described in ISO 22197-1 which was developed to characterize the photocatalytic activity of air-cleaning products was successfully applied to determine the photocatalytic activity of a bare TiO(2) powder. The experimental data reveal that at the light intensity stipulated by the operation procedure the amount of NO removed from the gas phase by photocatalytic oxidation is strongly affected by small changes of this light intensity as well as of the NO concentration in the gas stream in the photoreactor. Therefore, these parameters have to be controlled very carefully. Based upon the experimental data obtained in this study a rate law for the photocatalytic NO oxidation inside the photoreactor is derived.
氮氧化物造成的空气污染是城市地区的一个严重环境问题，因为大量的这些污染物集中在这些地区。减少这些空气污染物浓度的一种方法是在分子氧和光催化活性建筑材料（例如油漆、屋顶瓦或铺路石）存在下的光诱导氧化。本文介绍了在分子氧和 UV(A)辐照的 TiO(2)粉末存在下，氮(II)氧化物 (NO)的光催化氧化的研究结果。为了表征空气净化产品的光催化活性而制定的 ISO 22197-1 标准操作规程成功地应用于确定裸露的 TiO(2)粉末的光催化活性。实验数据表明，在操作程序规定的光强度下，通过光催化氧化从气相中去除的 NO 的量受到光强度以及光反应器中气流中 NO 浓度的微小变化的强烈影响。因此，这些参数必须非常小心地控制。根据本研究中获得的实验数据，推导出了光反应器内光催化 NO 氧化的速率定律。
