小分子羧酸与铁矿物相互作用及其环境光化学效应

天然有机小分子羧酸与铁矿物共存于自然环境中，二者之间的相互作用及光化学行为强烈影响着分子氧的活化，进而影响污染物的迁移与转化，而分子氧活化是发展绿色污染控制氧化技术面临的关键科学问题。然而，由于体系的复杂性，小分子羧酸耦合铁矿物的分子氧活化机制及其与污染物降解途径之间的关系仍不明确。本项目拟以赤铁矿和典型小分子羧酸为研究对象，系统考察其在光照下相互作用机制及光化学环境行为。通过分析羧酸在赤铁矿表面的吸附配位方式、羧酸铁配合物光生电荷动力学及铁溶出、液相中羧酸铁构型及分解方式，探究光生电荷转移与铁氧键断裂之间的关系，分析液相中铁物种光解行为对分子氧活化的影响，总结活性氧物种生成与羧酸铁配合物电荷转移、铁溶出等之间的内在联系，揭示羧酸诱导赤铁矿光化学活化分子氧的内在机制和典型有机污染物降解途径，为深刻认识环境污染物迁移转化机制、强化矿物对环境污染物的净化能力提供理论指导与技术支持。

The photochemical behaviors of iron minerals and carboxylic acid molecules play important roles on the oxygen activation and transformation of organic contaminants, owing to their widespread coexistence in the nature. However, under the light irradiation, kinds of different reactions occur simultaneously and multiple components are produced. It is still unclear about the mechanism of molecular oxygen activation and the pathway of contaminant degradation induced by the photo-generated charge transfer process. In this project, using advanced characterization methods and computational chemistry, the synergetic interactions between hematite and carboxylic acid molecules, such as oxalate acid, malonic acid, citric acid and their photochemical behaviors on the environmental remediation will be systematically investigated. In combination with the fundamental adsorption style and transformation processes of carboxylic acid molecules on the surface of hematite, the photo-generated charge transfer process will be studied in detail. Furthermore, the effects of the charge transfer on the molecular oxygen activation and the contaminant degradation pathway will be clarified. Finally, the mechanism of the typical contaminant decomposition based on iron minerals and carboxylic acid molecules will be summarized. This work can help to deeply understand the mechanism of migration and transformation of environmental pollutants, regulate the chemical transformation process of minerals and pollutants, and strengthen the purification capacity of minerals for environmental pollutants, which provides the prospect for the pollution control and environmental remediation.