水热碳层包覆的一维复合光催化剂的设计制备、结构调控及其光催化性能研究

This project proposer, in the previous work, has found that the coated hydrothermal carbon (HTC) layer can increase the catalytic performance of photocatalysts. However, there are still many issues need to be solved immediately: what is the optimal structure and property of the coated HTC layer, such as thickness, pore structure, and surface chemical property, to enhance the photocatalytic activity of photocatalyst? Which is the most important factor? What is the reaction mechanism? In this project, series of HTC layer-coated photocatalysts with 1D structure are synthesized by tuning the thickness, pore size, and doped heteroatoms of the HTC layer. The effect of HTC layers with various physical and chemical properties are systematically investigated by the surface adsorption for organics and the catalytic performance of the photocatatlysts. Meanwhile, various characterizations and experiments also will be employed to reveal their physicochemical, optical, and photoelectrochemical properties. Finally, a possible mechanism of the HTC layer is explored to explain the improvement of the photocatalytic performance. This project will provide a novel synthesis strategy to design and fabricate the photocatalysts with the coated structure and high photocatalytic activity.

申请人在前期研究工作中发现水热碳层包覆的复合光催化剂具有明显提高的光催化活性，但对于水热碳层的物理结构和化学性质（如厚度、孔道结构、表面化学性质等）如何影响光催化剂的催化活性，哪种结构是提升其催化活性的主要因素和水热碳层提升光催化活性的反应机理等核心问题仍需进一步研究。为此，本项目从调控水热碳层的厚度、孔道结构和杂原子表面改性等方面入手制备不同物理结构和化学性质的水热碳层包覆型一维复合光催化剂，考察其表面吸附行为和光催化活性，借助各种表征手段和实验方法对其物理化学性质、光学性质和光电化学性质等进行系统剖析，并提出水热碳层提升催化活性的反应机理。项目的实施将为制备包覆型高效光催化剂提供一种通用设计思路，指导更多具有表面吸附改性的复合光催化剂的开发和应用研究工作。

光催化技术被认为是一种有效脱除工业废水中有机污染物的绿色方法，但是该技术的大规模应用却极大地受限于光催化剂的催化活性。所以，本项目提出通过对光催化剂进行水热碳包覆处理，不仅极大提升了催化剂对有机污染物的吸附能力，而且大大提升了光催化剂催化降解有机污染物的反应活性。同时，本项目还证实当水热碳薄层的厚度调控为5 nm，并经过600 °C焙烧后，其对光催化剂催化性能的提升最为明显。基于此，一个可信的反应机理也被提出来解释水热碳层改进光催化剂催化性能的作用，此理论有望发展成为一个通用设计思路以指导更多该类型光催化剂的开发和研究工作。