高结晶度硼碳氮纳米片的制备及其光催化性能研究

Toward the pursuit of superior h-BCN photocatalysts, it is crucial to improve the efficiencies of charge separation and migration, while few systematic and in-depth researches on these issues have been reported to date. The h-BCN materials, which are synthesized by the ammonia pyrolysis method, have many surface defects and low crystallinity. In this project, we propose a novel photocatalyst configuration consisting of highly crystalline h-BCN nanosheets, which can be synthesized by adding suitable crystallization promoters, blowing agents and template agents during the ammonia pyrolysis process, as a novel research model to investigate the above issues. By using a series of characterization methods including spectroscopy and photo-electrochemical techniques, we will unravel the rules of interfacial separation as well as surficial migration and reaction for photo-generated electrons and holes. The performances in photocatalytic water splitting and photocatalytic oxidation of sulfur-organic compounds of the highly crystalline h-BCN nanosheets will be evaluated. Finally, we attempt to illustrate the interacting relationship within the crystallinity, morphology, charge dynamics and photocatalytic activities for h-BCN nanosheets. This project is proposed to develop high-quality h-BCN nanosheets that will greatly enrich the research content of photocatalysis.

发展高效硼碳氮(h-BCN)光催化剂的关键因素在于提高光生载流子的分离和迁移效率。当前针对此问题还没有比较深入和系统的研究。本项目针对高温氨解聚合法合成的h-BCN材料结晶度差，缺陷多、氮化不完全等缺点，拟通过添加结晶促进剂、发泡剂和模板剂等手段构筑高结晶度的h-BCN纳米片作为研究模型，利用光、电化学等多种实验手段了解光生电子与空穴的界面分离、表面迁移与反应的行为规律，同时结合该纳米片的光解水产氢、产氧、含硫有机物光催化氧化的催化性能，揭示h-BCN纳米片的结晶度、形貌-载流子行为-光催化性能之间的相互关系，本项目有望发展出高品质的h-BCN纳米片材料，将极大丰富光催化研究内容。

硼碳氮(BCN)材料的光催化效率受制于迟缓的光生电荷分离与迁移过程，同时BCN较差的抗氧化性也制约其实际应用。本项目通过调控结晶促进剂来优化反应条件与氮化过程，实现对材料的结晶度、能带结构、结构缺陷等性质的调控，促进光催化过程中光生电子空穴分离与传输，提高了光催化H2O2生成以及光催化甲硫醇脱硫的活性；此外，项目执行过程中还开发表面聚合技术合成面内高度结晶的氮化碳纳米片光催化剂，揭示了氮化碳纳米片面内有序度对其稳定性以及载流子分离与迁移的直接而关键的影响，从分子水平理解了氮化碳材料的构效关系。本项目在碳氮基光催化材料的设计调控和构效分析等方面进行了深入的研究，为后续新型高效稳定的光催化剂提供理论指导。