红磷多晶型体可见光催化产氢性能与机理研究

The elemental red phosphorus is a sort of novel visible-light-driven (VLD) photocatalyst with a wide response of solar spectrum. It shows great potential in photocatalytic hydrogen evolution by splitting water. However, most of literatures focused on amorphous red phosphorus, which has an unclear chemical structure. Thus, it brings the restrictions in optimizing the microstructures and explanations of photocatalytic mechanism. Meanwhile, it is still unknown for red phosphorus photocatalyst that its stability and the mechanism of deactivation during the photocatalysis. These problems have restricted the development of red phosphorus photocatalyst. Therefore, in this proposal, we plan to focus on other red phosphorus modifications, fibrous phase and Hittorf phase red phosphorus, which have the known single crystalline structure. Firstly, we plan to fabricate the single crystals, micro & nanostructures and the composites of fibrous phase and Hittorf phase red phosphorus. Then, we plan to study the relationship between their activity of hydrogen evolution and their crystalline structure, exposed facets, size and composite structures, aiming for further optimizing their photocatalytic activity. Meanwhile, we will study the correlation between the microstructure of red phosphorus modifications, their band structure/the separation and transport of their photoexcited carriers and their photocatalytic activity. This study will be conducted by combination of theoretical calculations, electrochemical and spectroscopic methods. Besides, we plan to study the mechanism of their activity lost and how to improve their stability during the photocatalysis. This project will offer the scientific evidences for understanding the photocatalytic mechanism of red phosphorus. Moreover, it will also promote the development of red phosphorus photocatalyst with high VLD photocataltyic hydrogen evolution activity.

单质红磷是一类新型宽光谱响应可见光催化材料，在分解水产氢方面极具潜力。但目前研究对象主要为无定形红磷，存在化学结构不清晰，难以进行微观结构调控和产氢机制阐释等问题，同时红磷在光催化产氢中的稳定性和失效机制尚不清楚，制约了红磷光催化材料的发展。为此，在本项目中我们拟以单晶结构已知的纤维相、西多夫相红磷多晶型体为研究对象，实现对二者单晶、微纳材料及复合材料的可控制备，研究其晶体结构、暴露晶面、尺寸、复合结构等与产氢活性的关联规律，优化红磷多晶型体的可见光产氢性能；同时结合理论计算、电化学和谱学手段，揭示红磷多晶型体的微观结构-能带结构/光生载流子分离、传输行为-产氢活性的关联规律；并研究其可见光产氢失效机制和稳定性增强手段。通过上述研究为深入理解红磷光催化作用机制，开发具有高效可见光产氢活性的红磷基光催化材料提供科学依据。

单质红磷是一类新型宽光谱响应可见光催化材料，在分解水产氢方面极具潜力。但目前研究对象主要为无定形红磷，存在化学结构不清晰，难以进行微观结构调控和产氢机制阐释等问题，同时红磷在光催化产氢中的稳定性和失效机制尚不清楚，制约了红磷光催化材料的发展。为此，在本项目中我们以西多夫红磷纳米晶、无定型红磷为主要模型，开发了一系列红磷基材料，通过控制反应条件等手段实现对二者单晶、微纳材料及复合材料的可控制备，特别是采用溶解热法，一步制备结晶度高的单相西多夫红磷纳米晶，研究了其晶体结构、暴露晶面、尺寸、复合结构等与产氢活性的关联规律，优化红磷多晶型体的可见光产氢性能；同时结合理论计算、电化学和谱学手段，揭示红磷多晶型体的微观结构-能带结构/光生载流子分离、传输行为-产氢活性的关联规律；并研究其可见光产氢失效机制和稳定性增强手段。通过上述研究为深入理解红磷光催化作用机制，为开发具有高效可见光产氢活性的红磷基光催化材料提供科学依据。另外，在本项目的支持下，开发了一系列其他类型的新型光催化材料，并深刻揭示了其在光催化分解、高级氧化和二氧化碳还原等方面的机理，并发表多篇高水平论文，进一步加深了对红磷基材料和其他新型半导体材料在光催化领域中的见解。