The lanthanide complexes [Yb(fac)₃(H₂O)₂, Yb(tta)₃(H₂O)₂, Nd(tta)₃(H₂O)₂] functionalized nanofibrillated cellulose (Ln-NFC) nanopapers with near-infrared (NIR) luminescence and high transparency are rapidly fabricated after solvent exchange using a simple suction filtration film-making method. The effects of NFC and lanthanide complexes content on their photophysical properties of Ln-NFC nanopapers and their mechanism of UV filters are fully investigated. With increasing lanthanide complexes content in the Ln-NFC nanopaper, their transmittances are gradually decreased while their NIR luminescences are obviously increased. Yb-fac NFC nanopaper has high UVB block rate at 298 nm, whereas the high UVA block ratio of Ln-tta NFC nanopaper is observed at 345 nm. Ln-NFC nanopapers show a much higher photostability without decomposition under UV irradiation at 365 nm over 5 h. The emission spectra of the Ln-NFC nanopaper process the NIR luminescence of the corresponding lanthanide ions through the efficient triplet–triplet energy transfer process. Ln-NFC nanopapers can bring a brilliant future for UV filters, labeling fields and marking soft materials application.

镧系元素络合物[Yb（fac）₃（H ₂ O）₂，Yb（tta）₃（H ₂ O）₂，Nd（tta）₃（H ₂ O）₂使用简单的吸滤膜制膜方法，在溶剂交换后，可以快速制备具有近红外（NIR）发光和高透明性的功能化纳米原纤化纤维素（Ln-NFC）纳米纸。充分研究了NFC和镧系元素络合物含量对Ln-NFC纳米纸光物理性质的影响以及它们的紫外线过滤机理。随着Ln-NFC纳米纸中镧系元素配合物含量的增加，其透射率逐渐降低，而其NIR发光则明显增加。Yb-fac NFC纳米纸在298 nm处具有较高的UVB阻挡率，而Ln-tta NFC纳米纸在345 nm处具有较高的UVA阻挡率。Ln-NFC纳米纸在5小时内在365 nm的紫外线照射下显示出更高的光稳定性，而不会分解。Ln-NFC纳米纸的发射光谱通过有效的三重态-三重态能量转移过程来处理相应镧系元素离子的NIR发光。Ln-NFC纳米纸可以为紫外线过滤器，标签领域和标记软材料应用带来光明的未来。