铁电材料Bi4Ti3O12(BTO)因优异的光催化活性可有效解决当今能源短缺和环境污染等问题备受关注，而有限的光谱响应范围和低的光生载流子迁移效率是影响其光催化性能的关键因素。针对此问题，本项目基于p型CuFe2O4(CFO)的窄带隙特性拓展光谱响应范围和Jahn-Teller(J-T)效应调控界面增强光生载流子迁移效率，提出构筑p-n结型BTO/CFO铁电复合材料并采用界面调控提高光催化性能的新思路。项目将深入研究p-n结的形成机理，探讨J-T效应、p-n结界面与铁电自发极化内电场间的关联性，分析p-n结界面调控对光生载流子迁移行为的影响规律，揭示基于J-T效应的p-n结界面调控机理和铁电自发极化内电场增强机制，构建光生载流子在p-n结界面内建电场和铁电极化内电场协同作用下的迁移模型，确立J-T效应调控p-n结界面对光催化性能的影响机制，为其他高性能铁电复合光催化材料的研发提供理论依据。

Ferroelectric Bi4Ti3O12 (BTO) has been receiving wide attentions owing to its excellent photocatalytic activity in handling the challenges of energy shortage and environmental pollution. However, its narrow light response range and low photo-generated carrier migration efficiency are limiting the further improvement of its photocatalytic performance. Therefore, in this project a p-type semiconductor with a narrow bandgap, CuFe2O4 (CFO) is selected to combine with n-type BTO to form a p-n junction and expand the light response range. Meanwhile, based on the Jahn-Teller (J-T) effect in CFO, the p-n junction interface will be regulate to enhance the ferroelectric polairization in BTO and then boost charge carriers separation. Through clarifying the formation mechanisms of p-n junction, the relationships among J-T effect, p-n junction interface and ferroelectric spontaneous polarization will be investigated, and the dependence of the photo-generated carrier migration behaviors on the interfacial regulation will be studied as well. Furthermore, the mechanisms of interfacial regulation and enhanced ferroelectric spontaneous polarization electric field will be explored. The synergetic effect of the p-n junction interfacial built-in electric field and ferroelectric spontaneous polarization electric field on the charge carrier migration will be established. Finally, the influence mechanism of interfacial regulation on the photocatalytic performance of BTO/CFO composite materials will be revealed. This project is expected to give a clue for developing other ferroelectric composite photocatalytic materials with excellent performance.