Synergistic multi-selective photocatalysis and real-time optical thermometry of CsPbBr₃/BiOI/TiO₂@PAN flexible nanofibers

Effective utilization of solar energy through photocatalytic oxidation is of great significance for environmental restoration and sustainable development. In order to realize the rapid separation of electron-hole pairs and improve the photocatalytic degradation activity, a multifunctional CsPbBr₃/BiOI/TiO₂ nanofiber photocatalyst with a symmetric double heterojunction structure is synthesized by combining electrospinning, hydrothermal and wet impregnation methods. Compared with powder photocatalysts, polyacrylonitrile (PAN) composite fibers work as a carrier offering the advantages of reusability, excellent flexibility, thermal stability, a controlled structure and a large specific surface area. Benefiting from the effective interfacial charge transfer and enhanced visible-light absorption, the obtained CsPbBr₃/BiOI/TiO₂@PAN nanofibers exhibit superior photocatalytic efficiency for rhodamine B, tetracycline hydrochloride, phenol and bisphenol A under simulated sun-light irradiation. Based on fluorescence intensity ratio (FIR) thermometry, the emission peaks of CsPbBr₃ at 516 nm and PAN at 479 nm can be utilized for accurate non-contact temperature monitoring and real-time thermal feedback in complex degradation systems, and the maximum relative sensitivity S_R is obtained as 0.0117 K⁻¹ at 353 K. In conclusion, multi-selective photocatalysis fibers with real-time optical thermometry properties provide new application prospects for water purification in extremely harsh environments.