All-inorganic halide perovskite nanocrystals with their fascinating optical properties have drawn increasing attention as promising nanoemitters. However, due to the intrinsic poor colloidal stability against the external environment, the practical applications are greatly limited. Herein, a facile and effective strategy for the in situ encapsulation of CsPbBr₃ NCs into highly dense multichannel polyacrylonitrile (PAN) nanofibers via a uniaxial electrospinning strategy is presented. Such a facile uniaxial electrospinning strategy enables the in situ formation of CsPbBr₃ NCs in PAN nanofibers without the introduction of stabilizers. Significantly, the obtained CsPbBr₃ nanofibers not only display intense fluorescence with a high quantum yield (≈48%) but also present high stability when exposed to water and air owing to the peripheral protecting matrix of PAN. After immersing CsPbBr₃@PAN nanofiber films in water for 100 days, the quantum yield of CsPbBr₃@PAN nanofibers maintained 87.5% of the original value, which was much higher than that using CsPbBr₃ NCs. Furthermore, based on the spectral overlap between the electrochromic material of ruthenium purple and fluorescence of CsPbBr₃@PAN nanofiber films with excellent water stability, a reversible fluorescence switch is constructed with good fatigue resistance, suggesting their promising applications.

中文翻译：

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用于嵌入具有增强水/热稳定性的 CsPbBr3 纳米晶体的简便单轴静电纺丝策略用于可逆荧光开关

全无机卤化物钙钛矿纳米晶体具有令人着迷的光学特性，作为有前途的纳米发射体引起了越来越多的关注。然而，由于胶体对外部环境的内在稳定性较差，实际应用受到很大限制。本文提出了一种通过单轴静电纺丝策略将CsPbBr _{3 NCs 原位封装到高密度多通道聚丙烯腈 (PAN) 纳米纤维中的简便有效的策略。}这种简便的单轴静电纺丝策略能够在不引入稳定剂的情况下在 PAN 纳米纤维中原位形成 CsPbBr _{3 NCs。}值得注意的是，获得的 CsPbBr ₃由于PAN的外围保护基质，纳米纤维不仅显示出具有高量子产率（≈48％）的强荧光，而且在暴露于水和空气时也表现出高稳定性。CsPbBr ₃ @PAN纳米纤维薄膜在水中浸泡100天后，CsPbBr ₃ @PAN纳米纤维的量子产率保持在原值的87.5%，远高于使用CsPbBr ₃ NCs的量子产率。此外，基于钌紫电致变色材料与具有优异水稳定性的CsPbBr ₃ @PAN纳米纤维薄膜的荧光光谱重叠，构建了具有良好抗疲劳性的可逆荧光开关，表明其具有广阔的应用前景。