石墨烯量子点/WO3超薄纳米片异质结的制备及光催化性能研究

增强可见光的吸收与提高光致电荷（电子和空穴）的分离效率是提高半导体光催化性能的有效途径。二维(2D)半导体纳米材料，具有超高的比表面积，表现出高度的各向异性、量子限域效应和极短的光生载流子扩散路径。石墨烯量子点异质结的构建，能增强对可见光吸收，提高了光生电子-空穴的分离效率。本项目将结合二者的优点，构建石墨烯量子点（GQDs）/超薄WO3纳米片复合光催化剂，研究2D超薄WO3纳米片、石墨烯量子点（GQDs）的合成方法及二者的耦合机制，提出设计高催化活性的GQDs /2D超薄结构复合材料的理论和方法。探讨材料表面光生电荷分离与复合、传输等动力学行为，深入揭示量子限域效应、异质结内建电场对光催化性能的影响机制。本课题的开展，将阐明2D超薄半导体及其异质结的光催化作用机理，为促进二维半导体材料在太阳光催化领域的应用提供重要依据。

Both enhancing the absorption of visible light and increasing separation efficiency of light-generated charge (electron and hole) are the effective way to improve the photocatalytic properties of semiconductor. Two-dimensional(2D) ultra-thin nanomaterials with super great surface area display high anisotropy、the quantum confinement effect and a very short carrier diffusion paths. Building graphene quantum dots(GQDs) heterojunctions, can enhance the visible light absorption and improve the light-generated electron - hole separation efficiency. The advantage of two aspects was combined in this project. We will design graphene quantum dots/2D ultra-thin WO3 nanosheets heterojunctions photocatalyst, and study the synthesis of GQDs、2D ultra-thin WO3 nanosheets and heterojunctions. The coupling mechanism of GQDs/2D ultra-thin WO3 nanosheets will be studied for propose the theories and methods of designing GQDs/2D ultra-thin nanosheets composites with high photocatalytical activity. In addition, it is investigated that the dynamic behavior of the surface photo-generated charge separation and recombination and transferring, so as to deeply reveal the influence of quantum confinement effect and built-in electric field of heterojunctions on photocatalytic properties. We will elucidate the photocatalytical mechanism of 2D ultra-thin conductor heterojunctions which will become an important basis for promoting two-dimensional ultra-thin semiconductor material applied in the field of sunlight catalyst