半导体光催化技术净化氮氧化物研究进展  

Research and development on nitrogen oxides removal by semiconductor photocatalysis

作　　者：姚婕 张宇飞 王雅文[1] 陈美娟[3] 黄宇[2] 曹军骥[2] 

机构地区：[1]太原理工大学化学与化工学院,太原030024 [2]中国科学院地球环境研究所中国科学院气溶胶化学与物理重点实验室,西安710061 [3]西安交通大学人居环境与建筑工程学院,西安710049

出　　处：《地球环境学报》2017年第6期492-505,共14页Journal of Earth Environment

基　　金：国家自然科学基金项目(41401567;41573138)~~

摘　　要：氮氧化物(NO_x)是形成臭氧和二次气溶胶的重要前体物之一,开发高效的NO_x控制技术对我国大气污染防治具有重要意义。光催化技术作为一种新型的高级氧化技术,对环境浓度水平的空气污染物具有良好的去除效果,是当前研究的热点。本文总结了近年来光催化材料对污染物NO_x催化降解的研究进展,包括:(1)讨论了NO_x光催化氧化去除机理;(2)详细综述了提高光催化材料性能的三大主要措施:增强催化剂的光吸收效率,提升载流子分离和迁移效率以及构筑表面活性位;(3)阐述了半导体光催化技术在净化空气方面的应用,并指出光催化技术在去除NO_x方面的发展前景。Background, aim, and scope In recent years, the haze phenomenon is more serious in China, especially in some typical cities. This phenomenon has a serious impact on climate, air quality and human health. Nitrogen oxides （NOx） is one of the main components of haze. And NOx （NO, NO2） generated from the combustion of fossil fuels have attracted lots of attentions, which can lead to a wide variety of atmospheric environmental problems, like acid rain, haze, photochemical smog and so on. The exhaust emissions of motor vehicle and combustion of fossil fuels are the culprit, which causing air pollution in urban environment. Therefore, taking effective measure and technical of control NOx levels in the atmosphere, which has an important practical significance to improve air quality of our country. Using solar energy to solve environment problem has attracted increasing attention. Photocatalysis technology can direct use solar energy to remove contaminants at room temperature. Therefore, photocatalysis is considered to potential technology for air purifcation. Materials and methods This paper reviews studies about the developments on NOx removal by semiconductor photocatalysis, focusing on photocatalytic mechanism, modifcations of photocatalyst, practical application and the development prospects in removal of NOx. Results When the semiconductor material is activated with light of wavelength equal to or greater than the band gap energy. The electrons of semiconductor valence band are stimulated transition to its conduction band, at the same time, the same number of holes left in valence band, thus creating electronic-hole pairs. Discussion According to the recognized photocatalytic model, the charge carrier difuse to the surface of catalysis. On the one hand, the holes with oxidizing ability can directly react with NOx. On the other hand, the holes also react with water molecules adsorbed onto the semiconductor surface to form OH·. The electrons can react with oxygen molecules to generate · . The OH· and · h

关 键 词：NOx NO光催化氧化去除机理 光催化剂 

分 类 号：X701[环境科学与工程—环境工程]