催化剂表面磁单元的构筑对光激发电荷迁移和光催化制氢行为的影响

This project will focus on the roles of magnetic unit over phototcatalyst and their impact on surface charge transfer and photocatalytic properties for photocatlytic hydrogen generation. The aim of this work will make further understanding of the basic question--variation and control of charge transfer over photocatalyst surface. By modification of the structure and properties of magnetic unit over graphene and C3N4, the charge transfer dependence on composition, morphology and surface functional group of magnetic unit will be studied in detail. In addition, their influences on photocurrent and photoactivity for hydrogen evolution will be investigated. By the time-resolved spectrum and mechanism calculation, we will know the performance of photo-excited charges and input electron by antenna molecule irradiated by visible light over graphene and C3N4, and the relationship between charge transfer and intrinsic magnetic field over catalyst surface. The potential results will help people to uncover the mechanism of enhancement of surface charge transfer, reducing of charge recombination and improvement of charge utilization driven by solar light. We hope this work will provide useful information for design and manufacture of high efficient photocatalyst for solar storage and conversion to hydrogen.

本项目通过在催化剂上构筑不同磁性的磁单元，研究表面微环境对表面电荷传输是如何影响的，进而如何影响到光催化剂的制氢性能这一基本的科学问题。通过对磁单元的结构、性质调整，详细研究磁单元的组成、结构、表面官能团不同以及磁单元的不同组合和配合对电荷传输及光电流和光催化性能的影响，以及通过时间分辨光谱和理论计算，进一步了解光激发产生的电荷及由染料分子注入的电荷在导电介质上的传输行为，研究这些行为与内磁场变化之间的关系，从而为调节和控制电荷在催化剂上的传输、降低电荷的复合几率、提高电荷的利用率，设计合成高效的光催化剂提供参考。

项目执行期间通过光分解原位沉积、化学沉淀、化学置换、水热、溶剂热、模板剂诱导、溶胶-凝胶及高温煅烧等多种方法优化组合的策略，以Fe3O4、Ni2P、NiSe、NiO和Fe2S2等为磁性单元，以还原氧化石墨烯、类石墨烯氮化碳、莫比乌斯环状碘化石墨烯、碘化类石墨烯氮化碳、胺化石墨烯、导电聚合物、氧化物或硫化物半导体等为光生电荷传输介质，以贵金属或其合金为助催化剂，构建了染料敏化-磁单元-载流子介质-助催化剂组合的多功能光催化剂与析氢新体系，研究了基于天线分子染料注入电荷的寿命以及所制备催化材料的光电流性质和光催化产氢性能变化、磁性单元变化（组成、结构、表面官能团）对电荷传输及光电流和光催化性能的影响，阐明了光激发电荷及由染料分子注入的电荷在导电介质上的传输行为与内磁场变化之间的关系，发展了基于磁单元调变电荷传输的催化剂材料组成结构设计原理。项目为调节和控制电荷在磁性光催化剂上的传输、降低电荷的复合几率、提高电荷的利用率、设计合成新型高效的磁性光催化剂提供了新策略，进一步拓展了光催化制氢材料的制备方法和体系。在国内外的重要学术刊物上如Appl Catal B、J Catal、J Mater Chem A、Nanoscale、Catal Sci Technol、ChemSusChem、Appl Surf Sci、J Magn Magn Mater、Chin J Inorg Chem等上发表研究论文38篇，他引1500余次。项目期间6名博士研究生毕业, 2名博士后出站。在国际会议上做报告4次。