Flexible PAN-g-C₃N₄-BiOI–AgI heterojunction nanofibers for enhanced photocatalytic degradation of RhB

A heterostructure nanofiber consisting of g-C₃N₄-BiOI–AgI with PAN as a carrier was successfully fabricated using electrospinning technology in this study. Compared to powdered photocatalysts, this structure offers advantages such as easy recovery and reusability. Morphological and compositional characterization revealed that the photocatalyst was uniformly distributed on the fiber surface, and the high specific surface area of the fiber promoted the photocatalytic reaction. The successful construction of the heterojunction was confirmed by XRD, HRTEM, and XPS analyses. Electrochemical impedance spectroscopy (EIS) showed that the heterojunction effectively suppressed electron-hole pair recombination, significantly enhancing the separation efficiency of photo-generated electrons. Photocatalytic experiments demonstrated that the synthesized PAN-g-C₃N₄-BiOI–AgI heterostructure markedly enhanced the degradation efficiency of Rhodamine B (RhB) when exposed to visible light. Mechanistic analysis identified ·OH radicals as the primary active species in the photocatalytic degradation process, with ·O₂⁻ as a secondary contributor. The photocatalytic rate constant of the PCBA5 sample in a 10 mg/L RhB solution was 1.04 × 10⁻¹ min⁻¹, which was significantly higher than that of PBA. After six cycles of experiments, the performance of the photocatalyst showed almost no noticeable decrease, demonstrating excellent stability and reusability. This study provides a strategy for designing recyclable photocatalytic materials, highlighting significant application potential.