芳香化g-C3N4催化剂高效光催化还原去除六价铀

With the development of nuclear power industry and nuclear strategy in China, and the demand for uranium resources is increasing. How to efficiently and effectively remove uranium pollution is a major scientific and environmental problem to be solved urgently. In this project,we will design thiophene, thiazole series aromatic g-C3N4 photocatalytic materials with using thermal polymerization and Schiff base reaction method for photocatalytically removing radioactive uranyl pollutant. Moreover, we will also study the effect of aromatic group composition, introducing morphology,and content on the light response range and intensity,the valence and conduction band potential, photoelectron generation, migration and use efficiency of the aromatic g-C3N4 in the photocatalytic reduction of uranyl pollution,furthermore the stucture-photoactivity relationship between electron structure and uranyl pollution efficiency of aromatic g-C3N4 will be, which will reveal its photocatalytic reduction mechanism. The stuy will suppy the theoretical and practical basis and suggestion for eliminating uranyl pollutant using photocatalytic reduction technology.

随着我国核电事业的发展和核战略需要，对铀资源的需求日益增长，将产生大量含有放射性核素铀的污水。如何高效、绿色地去除铀污染是人类迫切需要解决的重大科学和环境问题。本项目拟采用热聚合和schiff碱反应等方法，设计合成噻吩、噻唑等系列芳香化g-C3N4光催化材料，在可见光下，首次利用该系列光催化材料还原去除放射性铀酰。研究不同芳香基团组分、形态、含量对g-C3N4基光催化材料的光响应范围、强度，价带、导带电位，光电子产生、迁移以及利用效率的影响，建立芳香化g-C3N4电子结构与光催化还原铀酰效率之间的构效关系，揭示其光催化还原机理，为光催化还原去除铀酰污染提供理论与实践依据。

在核燃料循环的前端和后端，不可避免的会产生大量含U(Ⅵ)废水，寻找高效处理含铀废水十分重要，直接关系到核事业的可持续发展和核安全。相对于传统的处理工艺，光催化还原U(Ⅵ)由于其经济、高效、选择性强、无二次污染等特点展现出了广阔的应用前景。本项目通过9-蒽甲酸、2，5-噻吩二甲醛、2-氨基嘧啶和苯并呋喃-2-羧酸等有机化合物对g-C3N4进行芳香功能化，从分子尺度调控g-C3N4的电子结构和能带结构，拓展其π共轭体系，增强可见光吸收与光生电荷在g-C3N4内的高效传输，对可见光最大吸收波长从432nm扩展到500nm，促进U(Ⅵ)在光催化剂表面的吸附、活化和还原过程，提高g-C3N4在可见光范围内光催化还原去除U(Ⅵ)的性能，实现了光照30min去除水溶液中99%的U(Ⅵ)的高效光催化还原。同时，结合材料表征和实验结果，揭示各实验因素对光催化还原过程的影响，为g-C3N4在含铀废水处理领域提供理论和实践指导。