非金属表面等离子体共振效应及其增强上转换纳米材料发光的研究

The upconversion nanomaterials exhibit great potential applications in various fields including solar cells, photoelectric devices, photothermal therapy and so on. Unfortunately, the low upconversion emission efficiency hindered these applications. Plasmonic metal nanostructures have been widely used to enhance the luminescence of upconversion materials via the surface plasmon resonance effect. However, the high cost and earth rarity of noble metals limited their large-scale applications. Therefore, exploiting low-cost nonmetallic materials with surface plasmon resonance to enhance the upconversion luminescence of is of great research significance, and there are few reports. In this project, nanohybrid structures will be constructed by coupling nonmetallic plasmonic materials and upconversion nanomaterials. The synergy of nonmetallic surface plasmon resonance induced electric field enhancement and thermal effect is expected to realize the selective upconversion luminescence enhancement. Based on the high-intensity luminescence of upconversion materials and the photothermal effect of nonmetallic materials, the applications of the constructed nanohybrids in temperature detection, bioimaging and photothermal therapy for cancer cells will be explored. This project gives insight into the upconversion enhancement mechanism, provides an effective approach to enhance upconversion luminescence, and also opens up a new avenue for the application of nonmetallic nanomaterials.

上转换纳米材料在太阳能电池、光电子器件、光热治疗等领域都具有广阔的应用前景，但因其发光效率低而阻碍了它的进一步发展。目前，金属表面等离子体共振（SPR）增强上转换材料发光被广泛报道，但金属材料储量稀少、价格昂贵严重制约其大规模应用。因此，探究成本低廉的非金属SPR材料取代金属材料来增强上转换材料发光具有重要研究意义。基于此，本项目拟制备非金属SPR材料和上转换材料的纳米复合结构，利用非金属SPR局域场增强效应和光热效应协同实现上转换荧光的选择性增强。结合上转换材料的高强度荧光和非金属表面等离子体的光热效应探索复合结构在温度探测、癌细胞的生物成像、光热治疗等方面的应用。该项目的研究对深入理解上转换发光过程、增强机理有重要意义，将为探索高效增强上转换纳米材料发光提供新途径，同时为非金属纳米材料的应用提供新思路。

上转换纳米材料在太阳能电池、光电子器件、光热治疗等领域都具有广阔的应用前景，但因其发光效率低而阻碍了它的进一步发展。目前，金属表面等离子体共振（SPR）增强上转换材料发光被广泛报道，但金属材料储量稀少、价格昂贵，严重制约其大规模应用。因此，探究成本低廉的非金属SPR材料取代金属材料来增强上转换材料发光具有重要研究意义。基于此，本项目成功制备了非金属SPR材料氧化钨（WO3-x）和钨酸铋（Bi2WO6），并将其与上转换纳米颗粒复合，构建了非金属SPR复合结构UCNPs/WO3-x和UCNPs/BWO。利用非金属SPR局域场增强效应和光热效应协同实现上转换荧光的选择性增强，高达三个数量级（1200多倍），在非金属SPR增强上转换荧光方面达到了一个新的水平；非金属SPR复合结构可以作为荧光比率探针，实现宽范围和高分辨率的温度探测；结合高强度上转换荧光和非金属SPR光热效应，UCNPs/BWO纳米复合结构实现了癌细胞生物成像和光热治疗的双重功能。此外，非金属SPR纳米材料在乙醇脱水、水分解等反应中也展现出优异的光催化活性。该项目的研究对深入理解上转换发光过程、增强机理有重要意义，为非金属SPR纳米材料在生物医学、能源环境等领域的应用研究拓展了新思路。