基于Aurivillius-Sillenite结构光催化材料的性能调控研究

项目名称： 基于Aurivillius-Sillenite结构光催化材料的性能调控研究

项目编号： No.51472260

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 张玲

作者单位： 中国科学院上海硅酸盐研究所

项目金额： 83万元

中文摘要： 针对光催化材料中光生电子-空穴对容易复合、迁移效率低等容易导致光电转换效率低下的问题，本项目拟以二维超薄Aurivillius-Sillenite结构的光催化材料为研究对象，研究其晶体结构-材料维度-光催化性能三者之间的关系，探索影响光生载流子分离/迁移的内在机制等基础科学问题。具体包括：理论分析计算引入离子配位多面体对材料能带结构和成键机制的影响；制备出具有二维超薄结构的Aurivillius-Sillenite结构的光催化材料，研究离子配位多面体偶极矩极化效应与层间内电场相互协同作用对载流子分离/迁移的影响；对含有不同配位多面体及不同尺度的样品进行光催化性能表征，进而指导合成高效的光催化材料；将实验与理论预测结果相结合，揭示光生载流子在二维超薄Aurivillius-Sillenite结构材料中的分离/迁移规律，深刻认识光电材料中载流子输运的物理机制,实现对高效光催化材料的制备与应用。

中文关键词： 光催化材料；光生载流子；极化偶极矩；内电场；二维超薄结构

英文摘要： Photocatalysis is one of the major technologies for the energy and environmental fields, involving the production of fuels/chemicals and in the clean-up of hazardous or polluting wastes. However, the performance of photocatalyst is weakened by bulk recombination at large applied potentials. Therefore, attempts were made to increase electron-hole separation in these semiconductors. The 2-D nanosheet structured semiconductors with the Aurivillius-Sillen phases, would be found to be suitable for photocatalytic applications due to their unique layered structure and the existence of a strong electric field between the halide and [Bi2O2]2+ layer in favour of effective separation and diffusion of the electron-hole pair. It draws interest to reveal the relationship between the electron structures, crystal structures and photocatalytic properties as so to direct the research on photocatalysts to achieve high photocatalytic activities. This proposal focuses on (1)tailoring the composition and thereby the band gap of the semiconductors with Aurivillius-Sillen phases by the theoretical calculation.(2) We will tune the microstructures and band structure of the photocatalysts by inducing different ionic coordination polyhedron. The interaction between the ns2np0 electron lone-pair of Bi3+ and different ionic coordination will induce the deformation and polarization, which couples with the internal electric field will affect the band structure and diffusion of the charge carriers. (3)Photocatalytic activities of the as-synthesized samples will be evaluated by photoreduction of CO2 and water splitting. The relationship between the electronic configuration, crystal structure and photocatalytic properties would be set up and revealed.(4) The theoretical calculation and the experimental results will be used to interpret the influence of the ionic coordination polyhedron on the photocatalytic activities of the photocatalysts and to enhance the photocatalytic efficiencies. On the base of investigation of mechanism, novel and highly efficient visible light photocatalysts will be synthesized and applied.

英文关键词： photocatalyst;photogenerated carriers;polarization of dipole moment;internal electric field;2-D nanosheet