铁酸盐系纳米异/同质结构筑及多电子活化-可见光降解NOx机理

At present, nano-photocatalysis technology can be used to remove the low concentration of nitrogen oxides (NOx) in atmosphere. But the traditional nano-photocatalysts have some problems, such as the low adsorption and enrichment ability, high efficiency of photogenerated carrier recombination, etc. This project intends to controllably synthesize ferrite-based AFe2O4 (A=Zn, Mn, Mg) nano-heter/homojunctions materials with specific morphology and structure under the prediction and guidance of density functional theory (DFT) calculations. With the aim to achieve efficient adsorption of NOx and multi-electron activation of O2 in atmosphere, the lattice match phases that form nano-heter/homojunctions will be exposed for enhancing the visible light degradation efficiency. Through the combination of insitu characterization technique and DFT calculations, the directional growth mechanism of specific morphology and structure for AFe2O4 nano-heter/homojunctions will be first explicated; Next, the enhancement mechanism of the multi-electron activation-adsorption-diffusion characteristics of NOx and O2, carries migration and separation process, active sites and activation energy of catalytic reaction, key reactive oxygen species and environmental factors on visible light catalysis degrading NOx will be revealed. At last, the intrinsic relationship among the composition, surface/interface properties and catalytic activity of NOx for ferrite-based AFe2O4 nano-heter/homojunctions materials will be elaborated. In this project, a new nano-photocatalyst will be developed for the purpose of environmental air purification, which will provide a new idea for the development of environmental air pollution control technology.

传统纳米光催化材料在去除环境浓度氮氧化物（NOx）时存在吸附富集能力低、光生载流子复合效率高等缺陷，本项目拟借助密度泛函理论（DFT）计算预测材料定向生长机理，可控合成铁酸盐系AFe2O4（A=Zn, Mn, Mg）纳米异/同质结；并通过精细调控两相材料配比及高匹配度富Fe晶面暴露，实现环境浓度NOx的高效吸附富集和分子氧的多电子活化，提高可见光催化降解效率。结合原位动态表征与DFT计算手段，深入理解特定形貌AFe2O4纳米异/同质结定向生长机理，揭示其表界面上NOx和O2的吸附-多电子活化特性，确定环境因素对NOx可见光催化降解反应路径的影响，建立组成-形貌结构-表/界面性质-NOx催化性能间的内在关联。项目以环境空气净化为导向，开发新型高效纳米光催化材料，为环境大气污染治理实用技术的发展提供新思路。

针对传统单相催化材料的局限性，设计和发展了一系列高效纳米铁酸盐异质结光催化材料。通过材料化学组成与微纳结构调控探究了光催化过程中催化材料的结构组成与目标气相污染物NOx去除催化性能间的内在关联，揭示了其对光催化反应性能的影响规律，为铁酸盐异质结光催化降解NOx奠定了工作基础；结合理论计算模拟及实验结果揭示了异质结纳米光催化材料在可见光催化去除NOx过程材料界面的NO、O2吸附-多电子活化行为及载流子分离迁移路径调控机制，实现了环境浓度NOx的高效吸附富集和分子氧的多电子活化，提高了其可见光催化降解效率，为光催化削减环境大气中NOx浓度提供了有效策略；解析了异质结与降解NOx效率之间的构-效关系，通过鉴别关键活性物种及中间产物类型，明晰了NOx光催化降解反应机制。相关研究成果已发表国际高水平论文21篇、申请专利9项（其中7项已授权），并获得“陕西省科学技术进步奖”及“中国颗粒学会自然科学二等奖”，共培养博士研究生2名、硕士研究生5名，项目研究成果可为环境大气污染治理工程提供可靠的理论与技术支撑。