具有类石墨结构的氮化碳与碳纳米结构材料的复合及其光催化性能的研究

Semiconductive nanomaterials play crucial roles in solar cells, photocatalytic degradation of organic contaminants and photo-splitting of water to produce hydrogen. The key in such processes is to effectively use the solar light, which greatly depends on visible light active semiconductors with high quantum efficiency. Recently, graphitic carbon nitride (g-C3N4) is reported to be a visible light active semiconductor, while carbon nanotubes (CNTs) and graphene are good conductors and can be used as supports for catalysts. This project aims at studying the preparation, characterization and photocatalytic performance of composite photocatalysts composed of g-C3N4 and CNTs or graphene. g-C3N4 will be in situ synthesized on CNTs or graphene by carefully designed processes. The combination of g-C3N4 and carbon nanomaterials will greatly enhance the photocatalytic performance of the composite catalysts because of the synergy effect of the two components based on their electronic properties and structural similarities. The project will highlight the enhancement of photocatalytic activity by carbon nanomaterials on the basis of structural study and research on charge transfer properties of the composite catalysts. The results demonstrated in this project will shed light on exploring high performance photocatalysts for efficient degradation of pollutants using sun light and developing semiconductive nanomaterials for future applications in photon/electricity exchange and photoelectrical nanodevices.

半导体材料在太阳能电池、光催化降解有机污染物和光解水制氢等方面具有重要作用。其中的关键是太阳光的有效利用，核心是具有可见光活性和高量子效率的半导体材料。类石墨结构的氮化碳是新近报道的具有可见光活性的半导体；而碳纳米管和石墨烯是良好的导体和催化剂载体。本项目拟通过巧妙设计，在碳纳米管或石墨烯上原位控制合成氮化碳，研究具有类石墨结构的氮化碳与碳纳米管或石墨烯纳米复合材料的制备、表征及光催化性能。具有半导体性质的氮化碳与具有良好导电性能的碳纳米材料复合，实现两组份在结构和电性能上的协同作用，有利于纳米复合催化剂的生成及光催化性能的提高。本项目重点研究碳纳米材料对光催化性能的促进作用，从复合催化剂中各组份的结构及光生电荷转移性能上探讨如何提高半导体光催化性能的作用机理，为研制高性能光催化剂及发展半导体纳米复合材料在光电转换、光电微纳器件等方面的应用打下坚实的理论基础并积累丰富的实践经验。

本项目计划研究由碳纳米材料与g-C3N4组成的碳-氮化碳异质结催化剂，并对所制备的复合催化剂进行表征、催化剂性能测试和阐明纳米碳或其它纳米材料对半导体光催化性能的影响，探讨提高g-C3N4光催化活性的方法。本项目完成了采用多种原材料制备不同形貌的g-C3N4，并对其进行剥离处理，以提高比表面积，以及更易与其它材料复合，制备g-C3N4-基纳米复合光催化剂。成功制备了g-C3N4-石墨烯量子点、g-C3N4-微米碳球等碳-氮化碳异质结催化剂，在光催化分解水制氢中催化性能显著提高。研究了g-C3N4与多种半导体材料的复合催化剂，在光催化降解有机物、光电催化等方面具有良好的催化性能。对氮化碳基异质结催化材料的光催化机理进行了深入研究，为研制高性能光催化剂及发展半导体纳米复合材料在光电转换、光电微纳器件等方面的应用打下坚实的理论基础并积累丰富的实践经验。本项目至今发表SCI论文37篇。