氮氧化物（NOx）是导致城市灰霾发生的重要气态污染物之一，伴随着城市机动车及其他燃烧源排放的持续增加，NOx的控制依然为当前大气污染控制的难题。本研究拟针对环境大气中的低浓度NOx，开展常温常压下光催化技术对NOx的转化机制研究。前期研究表明纳米SrTiO3对NOx具有较好的吸附催化性能（Qian Zhang et al., 2016），本研究拟在此基础上调控纳米ATiO3（A=Ca,Sr,Ba）表面氧空位形成，提高NOx光催化活性及产物选择性。采用原位光谱表征与密度泛函理论计算研究氧空位纳米ATiO3（A=Ca,Sr,Ba）表面NOx的迁移转化规律，揭示吸附及关键催化活性位点；探讨影响NOx光催化性能的关键环境因素，揭示NOx在特定环境中的演变规律。本研究将探索NOx的光催化反应机理，深入认识大气环境中催化材料的介入对气态污染物转化的作用机制，为NOx污染减量提供必要的创新技术支持。

Nitric oxides (NOx) are one of the primary gaseous pollutants in air that lead to the occurrence of haze events. With the continuous increase of automobiles and burning sources in cities, the control of NOx emission still exist as a critical issue which needs to be solved. This project intends to study the photocatalytic conversion of NOx at room temperature and pressure. Our previous investigation shows that the perovskite strontium titanate (SrTiO3) nanomaterial exhibited excellent adsorption and photocatalytic performance for NOx at sub-ppb level (Qian Zhang et al., 2016). Further in this study, we propose to modulate the formation of oxygen vacancies on the surface of ATiO3(A=Ca, Sr, Ba) nanomaterials, with the aim to enhance photocatalytic removal of NOx and suppress the release of NO2. The in situ spectral characterization and density functional theory calculation will be employed to study the mechanism of photocatalytic NOx conversion over defect engineered ATiO3(A=Ca, Sr, Ba), and key active sites will be identified. The main environmental factors influencing the NOx removal efficiency will be elaborated, and conversion route be established. This project will explore the fundamental mechanism of NOx photocatalytic conversion, and provide novel technique for NOx reduction by realizing the effect of nano-catalytic material on air pollutant conversion at ambient conditions.