界面诱导的光生电荷微观行为与光催化体系的构效关系

The heterojunction structure can influence the performance in photocatalysis because that the interface may change the dynamic behavious of photo-induced charge carriers. The variation in the components and structure of an interface can impact on the transport direction, separation distance and recombination rate of photo-induced charges. Thus, the design and construct of a reasonable and effective heterojunction interface will be regulate and control the catalytic performance of photocatalysts through the microscopic dynamic behavious of photo-induced charge carriers. In this project, new photocatalytic materials with particular interfacial structures and compositions will be designed, and prepared through well selected synthesis strategies and the control of the reaction conditions. The photocatalytic performance of heterojunction photocatalysts in water splitting, conversion of organic molecules will be systematically evaluated. More importantly, the dynamic behaviors of photogenerated charges within photocatalytic system will be investigated. The separation driving forces and transport impact factors of the photogenerated charge will be clarified. The impact of the photogenerated charge behaviors on the functions of the photocatalytic materials will be carefully illustrated. The investigation performed in this project on the mechanism and functions of photogenerated charge behaviors is of fundamental and practical significance for the rational design and construction of novel materials with photocatalytic properties.

在光催化体系中，异质结构对光催化性能产生影响主要是通过改变光生电荷的微观动力学行为来实现的：界面电场的强弱为光生电荷的分离提供了不同的驱动力；电场方向决定了光生电子和空穴的传输方向；界面的组成和结构影响光生电荷的扩散和复合速率等等。因此，通过设计构筑合理有效的异质结界面，不仅能对光生电荷行为施加影响，更可以实现对光催化剂性能的调控。本项目拟从催化材料的设计合成出发，发展具有特定界面组成和结构的异质结催化剂的可控制备；围绕光生电荷在催化剂及反应体系内的微观行为进行深入研究，明确光生电荷分离的驱动力、传输的影响因素及复合速率等；针对光生电荷行为在水的分解等光催化体系中的行为与功效进行系统探索，建立光生电荷行为与反应活性之间的构效关系，实现对光生电荷行为和催化活性的调控。本项目对于开发新型的异质结构光催化材料、从微观层面认识光生电荷行为的机制与功效、促进光催化体系的实际应用具有重要意义。

本项目紧密围绕光催化研究和利用中存在的基本问题和需求，设计制备了多种具有异质结构（包括具有半导体/半导体、金属/半导体、金属或半导体/碳材料等界面结构在内）的光催化材料，并对材料在光催化分解水、二氧化碳、氨气等小分子的催化转化方面的应用进行探索；通过开拓新的合成方法与技术，实现对异质结构光催化材料的可控制备；将表面光伏、瞬态光伏等物理研究技术与化学方法相结合，研究光催化材料和光催化体系中的光生电荷行为特性，从微观层面上认识界面在催化反应中的作用机制；建立界面的组成结构、光生电荷行为调控、催化性能之间的关系模型；针对具有实际应用前景的反应体系，实现高活性材料的设计和宏量制备，探索光催化体系更广阔、更具体的应用前景。项目运行期间，发表SCI论文17篇；申请中国发明专利2项并获得授权。指导及联合指导硕士博士研究生10余名，其中已有2位同学获得博士学位、3位同学获得硕士学位。基本完成研究计划。