基于双边异质结的高效光催化及过程中氧气/水分子作用的基础问题研究

The ever worsened environmental pollution has greatly endangered the survival and development of human beings. Photocatalysis is one of the benign, sustainable and green methodologies to effectively resolve the environmental problems. However, nowadays the practical application of photocatalysis has faced the following challenges. a) low specific surface area and narrow absorption spectrum range of the recycle photocatalyst leads to low photocatalytic efficiency; and b) during the photocatalytic process, the role of oxygen and water molecules has not been verified with in-situ measurements. These problems have hindered the development and applications of photocatalysis in industrial applications. In order to solve these problems, we propose the following research for this project. a) We will use electrospinning to synthesize new large-specific-surface-area photocatalysts at low cost, with hetero-junction distributed along both internal and external sidewalls. We will use energy band manipulation and surface plasmon enhancement to extend the spectrum absorption range for the photocatalysts; b) we will simulate various atmosphere conditions for the photocatalytic degradation of organics in order to verify the roles of water molecules in the photocatalytic process, using dynamic real-time tracking to observe the byproducts during the photocatalytic degradation process. This project will provide effective and new methods for the application of photocatalysis in extreme conditions and for the improvement of photocatalytic efficiency.

环境污染威胁着人类的生存与发展，光催化是一种绿色、廉价、满足可持续发展的需求并有效解决环境污染的重要方法。然而，在实际应用中光催化面临如下问题： a）可回收型光催化剂的比表面积小和光谱吸收范围窄，使其光催化效率低；b)催化过程中的氧气与水分子的作用本质尚未得到原位验证，从而不能指导与设计新型高效光催化剂。这些问题阻碍了光催化的发展与实际应用，特别是光催化在极端条件下的应用。针对这些问题，本项目a)拟基于电纺丝技术制备新型、高效、廉价的具有大比表面积的双边异质结光催化剂，同时通过能带调控及引入表面等离子体共振增强吸收的方法扩展其光谱吸收范围；b)模拟多种系统条件进行光催化降解有机物的研究，对光催化降解过程进行实时追踪，从而掌握并阐明光催化过程中水分子的作用机理。本项目将为光催化效率的提高提供新的有效方法和途径，为光催化在极端条件下的应用提供理论支持。

环境污染威胁到人类的生存和发展，开辟一条绿色的能降解有机污染物的有效途径是十分必要的。光催化降解有机物是将光能转换成为化学反应所需的能量，从而分解对人体和环境有害的有机物质。光催化技术不仅能降解污染物，且不会造成资源浪费与附加污染，因此光催化的研究备受各国政府与科研机构的关注。目前，商业中通用的光催化剂一般为比表面积极大的P25，但其颗粒直径小，易引发二次污染和催化剂的大量浪费，且TiO2 仅能吸收紫外光，使其光催化效率低。因此研发具有高光催化效率、可重复利用、廉价的光催化剂是十分重要的。本项目首先基于电纺丝直接制备具有极高的比表面积、良好的便于电子-空穴对溢出的结构、光谱吸收范围广的基于TiO2 的双边异质结光催化剂。利用气敏探测仪、质谱仪、红外光谱仪等对各种模拟气相环境的光催化过程进行原位动态的跟踪与比对，研究了干燥环境中的光催化，从而掌握光催化过程中水分子的具体作用机理。（在制备催化剂的过程中制备了三维石墨烯，发现三维石墨烯具有良好的铝电池性能。）发表了包括Nature在内的高水平论文近20余篇。