高热稳定性介孔黑TiO2纳米材料的表面缺陷调控及其组装体的制备与光催化性能研究

The purpose of this project is to design and synthesize the high thermostable mesoporous black TiO2 and their composites, and control the surface defects, which possess high visible light photocatalytic performance. The lyotropic liquid crystal mesophase of specific structure is formed via evaporation-induced self-assembly approach, realizing the dual preferred orientation for mesoporous TiO2 channel and crystallographic plane through controlling the channel and crystal orientation. The mesoporous frameworks are stablized via small amine molecules solidification strategy, which could not be collapsed under high-temperature treatment conditions. The high thermostable mesoporous black TiO2 visible-light-driven photocatalysts with controllable surface defects can be obtained through controlling the reducing conditions. The heterogeneous constituents are assembled into the mesoporous channels through pressure-induced assistant technique, and fabricating multi-functional heterojunction composites. In order to promote the practical application process of the mesoporous black TiO2 and their composites in photocatalytic fields, the microstructure change of materials during photocatalytic process, the effect of photocatalytic performance for photocatalytic active center and electronic structure change, the essence of interaction between heterogeneous constituents, the relationship of mesoporous black TiO2 between the structure and property, the surface energy level of the composites, the reaction dynamics process and the mechanism of energy transfer, the information of transfer, separation and recombination for photogenerated charge carriers will be also performed, utilizing the theoretical calculation combined with transient photovoltaic characterization methods and time-resolution synchrotron radiation quick X-ray absorption fine structure (QXAFS) technique.

本项目拟设计合成高热稳定性介孔黑二氧化钛及组装体，调控其表面缺陷，制备高性能可见光催化材料。采用蒸发诱导自组装方法形成特定结构的溶致液晶介相，调控其孔道和晶粒取向，实现对二氧化钛孔道及晶面的双重择优取向，采用小分子胺固化策略稳固介孔骨架，使其高温不塌陷，控制还原条件得到表面缺陷可控的高热稳定性介孔黑二氧化钛可见光催化材料。采用压力诱导辅助技术将异质组分组装到介孔孔道内，构筑多功能异质结组装体。理论计算结合稳态光伏和时间分辨同步辐射快速XAFS原位测试技术确定光催化反应过程中材料的微观结构变化，探测光催化反应活性中心及其电子结构变化对光催化性能的影响，揭示异质组分之间相互作用的本质及材料结构与性能之间的关系、复合体表面态能级以及光生载流子的动力学过程和能量传递机制，提供载流子迁移、分离和复合等表面态信息，进而明确光催化反应机制，推动高热稳定性介孔黑二氧化钛及其组装体在光催化领域的实用化进程。

本项目设计合成了高热稳定性介孔黑二氧化钛及其组装体材料，通过缺陷工程调控其表面缺陷制备了高性能太阳光驱动的光催化材料。采用蒸发诱导自组装、溶剂热方法形成特定结构的溶质液晶介相，实现了对介孔二氧化钛孔道和晶面的择优取向，采用小分子胺固化策略稳固介孔骨架，使其高温不塌陷，控制高温氢化、固态化学还原等策略得到表面缺陷可控的高热稳定性有序介孔黑二氧化钛、介孔黑二氧化钛空心球、介孔黑二氧化钛纳米管及二维超薄介孔黑二氧化钛纳米片可见光催化材料，其光催化性能较原始样品提高了5-10倍。然后将其作为宿主，采用湿浸渍、水热、沉积、光还原等策略构筑了系列高热稳定性介孔黑二氧化钛组装体材料，例如串联异质结、Z型异质结等，拓展了可见-近红外光的吸收，并进一步提高了太阳光驱动的光催化性能。理论计算结合稳态光伏、时间分辨荧光光谱、同步辐射测试技术确定了光催化反应材料的微观结构变化，探测了光催化反应活性中心及其电子结构变化对光催化性能的影响，揭示了异质组分之间相互作用的本质及材料结构与性能之间的关系，提供了载流子迁移、分离和复合等表面态信息，进而明确了光催化反应机制，以推动高热稳定性介孔黑二氧化钛及其组装体在光催化领域的实用化进程。此外，结合光催化领域研究现状，开展了漂浮型多孔黑二氧化钛太阳光催化材料的实用化探索，拓展了高热稳定性介孔黑二氧化钛光催化材料在环境领域的应用。