负载型离子液体@金属硫化物量子点光催化固氮合成氨体系的构筑及其性能研究

光催化固氮合成氨技术为温和条件下氨的清洁高效生产提供了一条新途径。但氮气在水相反应体系中较低的溶解度和较慢的扩散速率，严重制约了光催化固氮反应效率的提升，使该技术的实用化进程备受限制。本项目提出构建具有量子点结构的负载型离子液体@金属硫化物光催化剂，一方面基于功能化离子液体优异的气体溶解性，实现水中氮气分子的快速扩散和吸附；另一方面基于离子液体特殊的结构导向作用，引导金属硫化物形成量子点结构，促进N≡N键的高效解离活化及电子和质子的快速转移；在单一催化剂内实现对氮气分子的溶解扩散和解离活化两大过程的有机协同，达到大幅提升固氮合成氨性能的目的。通过系统制备、表征和活性评测分析研究，揭示负载的离子液体对氮气分子溶解、扩散和吸附等传质过程的影响规律，阐明离子液体和金属硫化物量子点结构协同强化电荷迁移和氮还原反应等动力学过程的作用机制。为光催化固氮合成氨新材料体系的开发提供理论依据和优化设计原则。

Photocatalytic nitrogen fixation for ammonia synthesis technology provides a new way for the clean and efficient production of ammonia under mild conditions. However, the lower solubility and diffusion rate of nitrogen in the water-phase reaction system severely restricts the performance of photocatalytic nitrogen reduction, therefore limiting the practical application of this technology. This project proposes the construction of ionic liquid @ metal sulfide photocatalyst with quantum dots structure. Based on the excellent gas solubility of some functionalized ionic liquids, the rapid diffusion and adsorption of nitrogen molecules in water-phase are realized. Additionally, the unique characteristics of ionic liquids allow formation of metal sulfide quantum dots structure to be carefully controlled due to the structure-guided effect, which promotes the efficient dissociation and activation of N≡N bonds and the rapid transfer of electrons and protons, as result of realizing the synergism of dissolution and diffusion processes of nitrogen molecules in a single catalyst. These factors allow the catalyst to achieve the goal of greatly improving the performance of nitrogen reduction. Through systematic preparation, characterization, and activity evaluation analysis research, the law of mass transfer processes such as dissolution, diffusion, and adsorption of nitrogen molecules in the ionic liquids system can be resolved, and clarify the mechanism of the synergetic enhancement of charge transfer and nitrogen reduction by ionic liquid and metal sulfide quantum dots structure. It provides theoretical basis and optimized design principles for the development of novel material system of photocatalytic nitrogen fixation.