外场作用下铋层状铁电材料的畴结构演化与吸附/催化性能的构效关系

Ferroelectric materials have shown unique advantages because of their polarization effect and anomalous photovoltaic effect when applied to photocatalysis. However, there is still a lack of deep research on the structural and property relationship of ferroelectric catalysis, which greatly restricts further design of the materials. In view of the fact that ferroelectric materials have rich domain structures and the domain structures can respond to external field, this project intends to carry out the study on the structure-activity relationship between the domain evolution of ferroelectric materials and the surface adsorption and catalytic properties under the action of external field, by drawing on the successful experience of the regulation of domain structures and polarization performance in the traditional ferroelectric field.Concrete implementation of the project is as follows: Firstly, synthesis a series of bismuth layer-structured ferroelectric nanosheets with different surface structures by means of elemental substitution and synthesis methods regulation. Then, study the influence and regulation of surface atoms arrangement as well as strain adjustment to the domain structures and the local piezoelectric response by atomic force microscope. Further, investigate the effects and mechanism of adsorption and catalytic behavior of the gaseous molecules (CO2, CH4 and C2H4) on the ferroelectric nanosheets with various polar faces and domain states by combining with programmed temperature desorption and other in-situ spectroscopic characterization techniques. The study would be benefit for extending the application of ferroelectric materials as well as further designing high performance catalystic materials that utilizing solar energy.

铁电材料因其极化效应和反常光伏效应应用于光催化研究已展示出独特优势。然而，关于铁电催化的结构性能关系仍然缺少深刻的研究，这极大地制约了进一步的材料设计。考虑到铁电材料丰富的电畤结构及随外场变化的特性，本项目拟借鉴传统铁电领域中关于电畴结构与极化性能调控的成功经验，开展在外场作用下铁电材料的畴结构演化与表面吸附和催化性能的构效关系研究。项目的具体实施拟以铋层状钙钛矿铁电材料为主要研究对象，通过元素取代和合成方法优化，制备出具有不同表面结构的系列铁电纳米片样品，进而借助原子力显微镜研究表面原子排布和应变调控对其电畴结构和局域压电响应的影响与调控规律，结合程序升温脱附和其他原位谱学表征技术协同研究铁电纳米片不同极性表面和电畴反转等对气态小分子(O2、CO、CO2和CH4等)的吸附和催化行为的影响和作用机制，为拓展铁电材料的应用领域和设计高性能光（热）催化材料提供知识储备和材料技术支持。

铁电材料因其极化效应和反常光伏效应应用于光催化研究已展示出独特优势。然而，关于铁电催化的结构性能关系仍然缺少深刻的研究，这极大地制约了进一步的材料设计。本项目通过颗粒形貌、显微结构、电畴状态等调控手段，设计合成了系列具有优异极化特性、光电和催化性能的极性光电功能材料，阐明了其构效关系并取得了若干创新成果：通过BiOX (X=Cl, Br, I)微纳米片的可控合成，证实其具有局域压电响应及良好的光电转换能力；通过纳米氧化锌的晶面调控及表面修饰，提升了甲烷光氧化活性并阐明其与乙烯光氧化的异同；通过铋层状铁电陶瓷的微结构调控，显著提升了其极化特性并发现一种基于铁电材料弯曲变形的电致伸缩新模式；通过对反铁电铌酸银陶瓷的体光伏效应及其表面压电性的研究，阐明了铁电光伏和应变光伏的异同；通过镧改性锆钛酸铅铁电陶瓷光致伸缩效应的再研究，阐明了光致电荷转移诱导晶格重构的光致伸缩新机制，并在钒酸铅无机固体中发现光诱导的双向形变新现象；通过对前述工作的总结，阐明了铁电光催化的物理化学基础。已在Matter, Materials Today, Advanced Materials, Advanced Functional Materials等国际期刊发表SCI 收录论文26篇，其中大类I区论文7篇，期刊封面或背封面论文4篇，培养博士生3名、博士后1名、硕士生5名。