金属氧化物半导体多壳层中空结构的可控合成与光解水性能研究

本申请拟将理论预测与实验验证相结合，对多壳层金属氧化物中空纳微结构材料进行结构设计、组分调控和性能优化，以增强光捕获能力、扩大光吸收范围、强化光生电荷分离以及促进表面反应等，实现高活性、高稳定性的全水分解光催化剂的创制。采用时域有限差分方法，研究金属氧化物的多壳层中空结构与其光捕获性能的关系，在此基础上进行多层次的介观结构与组成设计。采用“次序硬模板法”，通过模板前处理、强化吸附等策略，实现多壳层中空结构金属氧化物的可控合成；通过调控壳层数目、壳层间距和壳层厚度，提高材料对光的有效吸收；通过构建异质界面和减小壳壁厚度等，强化光生电子与空穴的分离；通过调控孔结构及表面的亲疏水性，加速催化反应的进行。从材料的催化活性及稳定性两个方面系统地考察制备的多壳层中空结构金属氧化物的光解水产氢产氧性能，揭示催化材料的多级结构及组分与其光催化性能的构效关系，为高效光催化材料的开发奠定基础。

In this project, the applicant plans to develop metal oxides with hollow multishelled structure (HoMS) for the purpose of enhancing their solar water splitting properties. It is proposed to combine theoretical prediction with experimental verification to optimize the structure and composition of HoMS, in order to increase the light absorption ability, expand the light absorption range, boost the separation efficiency of the photogenerated charge carriers, and promote the mater transfer, etc. Firstly, the finite-difference time-domain method will be used for studying the relationship between the structure of HoMS and the performance of light harvesting ability, and designing the structure on the basis of this theoretical calculations. Secondly, this project will focus on the systematical and in-depth investigation on controllable synthesis of HoMS. Structural parameters of HoMS including the shell number, shell thickness, inter-shell space, pore size distribution, as well as the surface properties and so forth will be manipulated by pre-treatment of the templates or strengthen the ion penetration of metal ions within the templates. The hierarchical structure of HoMS may enable multiple light scattering and reflection, thus increasing the light harvesting efficiency. The thin shells can shorten the diffusion paths for photo-excited electrons and holes, thus benefitting the charge separation. And the surface hydrophilicity can be also well-controlled to facilitate surface reaction. Finally, hydrogen evolution activity and oxygen evolution activity of the synthesized HoMS will be studied systematically. The structure-function relationship between structure and solar water splitting properties will be revealed, which then promote the development of photocatalysts with high activity and high stability.