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

Abstract

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.