以多孔氮化硼为载体的高效、稳定稀土杂化发光材料的开发

Lanthanide complexes often possess excellent luminescent properties but poor thermal stability. Based on the idea of “multifunctional hybrid”, incorporation of lanthanide complexes into porous material to form organic–inorganic hybrid materials, is an effective way to improve their stability. The luminescent hybrid materials can find promising applications in the field of display, lighting and biomedical. This project chooses porous boron nitride as a novel host material for lanthanide complexes. The Eu(III) and Tb(III) complexes with red/green light emitting in visible region will be incorporated into the porous BN matrix to form newly luminescent hybrid materials. The porous BN has adjustable pore size, high specific surface area, good thermal and chemical stability, excellent optical transparency, and high thermal conductivity. These properties indicate that porous BN can be used as promising host materials to improve the stability and luminescence reliability of the lanthanide complexes. Most importantly, compared to traditional host materials, such as mesoporous silica and zeolites, porous BN have π-bonded structure. The special microporous environment is expected to play a unique role for the adjustment of the luminescence. In this project, various lanthanide complexes will be incorporated into porous BN with different pore structures, and the impact of porous BN host on the luminescence properties and stability of the lanthanide complexes will be revealed. Finally, the luminescent mechanism of the hybrid materials will be clarified. The expected outcomes of this research will be very important for the development of novel lanthanide complex-based hybrid luminescent materials with high efficiency and excellent stability.

基于多功能杂化和复合的思想，将具有优异发光性能但稳定性不佳的稀土有机配合物嫁接到多孔材料中形成杂化发光材料，可以有效改善其稳定性，在显示、照明、生物医学领域有重要的研究及应用价值。本项目选择多孔氮化硼(BN)作为稀土配合物的新型主体基质，将在可见光区产生强红、绿光发射的Eu(III)及Tb(III)稀土配合物引入多孔BN中。由于多孔BN具有孔径可调、比表面积高、热和化学稳定性好、透光性能优良、热导率高等特点，对提高稀土配合物稳定性和发光可靠性具有优势。更重要的是，与传统硅基介孔材料、沸石等基质相比，多孔BN特殊的富含π键的微孔环境，有望对稀土配合物发光起到独特的调节作用。通过对不同微结构的多孔BN与稀土配合物的功能化组装，研究稀土配合物在多孔BN中的分布，揭示多孔BN对稀土配合物稳定性和发光特性的影响，进而阐明杂化材料发光机理。本项目将为最终开发出高效、稳定的新型稀土杂化发光材料奠定基础。

以多孔固体材料作为基质，将具有优异发光性能但稳定性不佳的发光材料与多孔基质复合实现功能化组装，可以有效改善其化学微环境，提高其稳定性，对于获得高效、稳定的发光材料具有重要意义。本项目以具有高比表面积、大的孔体积、良好的化学稳定性的多孔氮化硼（BN）作为主体基质，通过与具有优异发光性能但稳定性不佳的稀土配合物发光材料相复合，制备出系列新型功能化杂化发光材料，研究了杂化材料中各组分之间的相互作用机制，揭示了多孔BN对发光组分的稳定性和发光特性的影响，实现了杂化材料的发光调控和稳定性提升。本项目取得的重要成果包括：发展了冷冻干燥法制备具有超细直径、高比表面积的多孔BN纳米纤维，通过改变高温热解温度实现了纤维比表面积和孔结构的调节，通过改变前驱体形核过程合成了由多孔BN纤维构筑的大尺寸超轻BN泡沫；以多孔BN微米纤维作为基质，引入具有不同配体的Eu、Tb配合物，合成了具有良好稳定性的系列稀土配合物/多孔BN杂化发光材料，发现了多孔BN基质和稀土配合物之间存在独特的协同效应，使得BN-配体-稀土离子系统中存在着有效的能量传递过程；以多孔BN作为基质对多种组分、不同颜色的稀土配合物进行功能化组装，通过调节配合物比例成功实现了杂化材料在可见光范围内从绿光到红光的发光调控；将多孔BN与有机荧光染料进行杂化复合，利用多孔BN的孔道限制作用实现了荧光染料罗丹明B的发光效率和热稳定性的提升，获得了高达86.94%量子效率的非稀土红色荧光粉；以多孔BN纳米纤维作为载体，将无机金属卤化物钙钛矿量子点负载于其表面，获得了具有良好光稳定性和长期储存稳定性的复合荧光粉，拓展了多孔BN的应用方向。项目执行期间发表SCI论文28篇，会议报告5次，申请发明专利4项。