基于空间限域效应的D-A型PCN@FexOy可控构筑及其原位光-芬顿降解有机紫外线过滤剂机理研究

近年来，有机紫外线过滤剂（OUVFs）在水环境中不断被检测出，急需发展高效OUVFs深度处理技术。光-芬顿技术能够高效降解各种难降解污染物，为解决OUVFs污染问题提供了一种潜在途径。然而，目前光-芬顿技术存在两个关键问题：需要外加H2O2和H2O2活化产生羟基自由基效率低。因此，本项目拟构筑表面官能团和共轭程度可调多孔给体-受体型PCN，通过光催化氧分子还原实现H2O2高效生成。在此基础上，将FexOy纳米粒子封装到PCN孔道内并原位激发光生H2O2实现OUVFs高效降解。通过系统研究，阐明表面官能团和共轭程度对给体-受体型PCN激子解离/电荷分离、H2O2产率和氧分子两电子还原选择性影响机理；揭示空间限域效应对OUVFs吸附、降解效率/降解途径影响规律和机理。该项目研究成果将为高效原位产H2O2光-芬顿体系理性设计提供新思路，也将为实际水环境中新兴污染物高效去除提供理论依据和技术支持。

In recent years, organic UV filters (OUVFs) have been continuously detected in the water environment and it is urgent to develop efficient OUVFs advanced treatment technology. Photo-Fenton technology can efficiently degrade various refractory pollutants, which provides a potential way to solve the pollution problem of OUVFs. However, there are two key problems in current photo-Fenton technology: the need for additional H2O2 and the low efficiency of H2O2 activation to produce hydroxyl radicals. Therefore, this project intends to construct a porous donor-acceptor PCN with adjustable surface functional groups and conjugation degree, and realize the efficient generation of H2O2 by photocatalytic reduction of oxygen molecules. On this basis, FexOy nanoparticles were encapsulated into the channel of PCN and photogenerated H2O2 was excited in-situ to realize the efficient degradation of OUVFs. The effects of surface functional groups and conjugation degree on exciton dissociation/charge separation, H2O2 yield and two-electron reduction selectivity mechanism of donor-acceptor PCN were investigated systematically; the effects of spatial confinement on the adsorption and degradation efficiency/pathway of OUVFs were investigated. The research results of this project will provide new ideas for the rational design of an efficient in-situ H2O2 production photo-Fenton system, and also provide theoretical basis and technical support for the efficient removal of emerging pollutants in the actual water environment.