Abstract: Dye wastewater pollution has become one of the most pressing environmental issues facing society today. With the rapid development of industries such as textiles, printing and cosmetics, a large amount of dye wastewater is discharged into the natural environment, causing serious water pollution. Dye molecules not only harm aquatic plants and animals but also pose a threat to human health. Therefore, developing efficient and eco-friendly photocatalytic materials to treat dye wastewater has become an important research direction in the field of environmental governance in recent years. 
Graphitic carbon nitride (g-C3N4) has attracted significant attention for its excellent photocatalytic properties. In this study, protonated g-C3N4 nanoparticles (PCN) were synthesized using a molten salt-assisted method followed by hydrochloric acid treatment, and protonated g-C3N4/polyacrylonitrile (PCN/PAN) nanofiber membranes were successfully prepared using electrospinning technology. Characterization techniques, including SEM, TEM, XRD, XPS, and FTIR, were used to analyze the surface morphology and chemical structure of the PCN/PAN nanofiber membranes. The results confirmed that the protonated g-C3N4 nanoparticles were successfully loaded onto the PAN nanofiber membranes and uniformly distributed within the nanofibers. The optical properties of the nanofiber membranes were characterized using UV-Vis DRS testing. The study found that the PCN/PAN5 nanofiber membranes exhibited high light absorption capacity within the visible light range, indicating their strong photocatalytic activity. The photocatalytic performance of the nanofiber membranes was investigated by photocatalytic degradation of rhodamine B (RhB). Compared to CN/PAN3 nanofiber membranes, PCN/PAN3 nanofiber membranes demonstrated approximately 1.6 times higher photocatalytic efficiency. With an increase in the mass fraction of protonated g-C3N4 nanoparticles, the PCN/PAN5 nanofiber membrane demonstrated the highest photocatalytic degradation efficiency, reaching 97.96%. Furthermore, after 10 cycles of use, the photocatalytic degradation efficiency of the PCN/PAN5 nanofiber membrane remained above 92%, demonstrating its excellent cyclic stability. The photocatalytic degradation mechanism of PCN/PAN5 nanofiber membranes was further discussed through these experiments. The results indicated that the high crystallinity of the protonated g-C3N4 nanoparticles and their good dispersion within the PAN fibers were key factors in enhancing its photocatalytic performance.
In summary, a photocatalytic material with excellent performance was prepared by synthesizing protonated g-C3N4 and optimizing its loading in PAN nanofiber membranes in this study. The results showed that the introduction of protonated g-C3N4 nanoparticles significantly improved the photocatalytic efficiency of the nanofiber membranes and exhibited good cycling stability. This paper provides new insights for the development of efficient and stable photocatalytic materials, holding great significance for the practical application of dye wastewater treatment.

Key words: protonated g-C3N4 nanoparticles, electrospinning, nanofiber membranes, photocatalytic performance

摘要： 为制备高性能光催化材料，采用熔盐辅助法与盐酸处理合成了质子化g-C3N4纳米颗粒，并利用静电纺丝技术成功制备了质子化g-C3N4/聚丙烯腈(PCN/PAN)纳米纤维膜。通过X射线衍射、扫描电子显微镜、透射电子显微镜、傅里叶变换红外光谱、X射线光电子能谱、紫外-可见漫反射光谱等对PCN/PAN纳米纤维膜化学结构、形貌和光学性能进行表征，并评估了其对罗丹明B(RhB)溶液的光催化降解性能。结果表明：当质子化g-C3N4的质量分数达到5%时，纳米纤维膜的光催化降解效率可达97.96%；经过10次循环使用后，该纳米纤维膜的降解效率仍能保持在92%以上，展现出了优异的光催化性能和循环稳定性。制备的PCN/PAN5纳米纤维膜为高效光催化材料的设计提供了新思路，并在染料废水处理方面展现了良好的应用前景。

关键词: 质子化石墨氮化碳纳米颗粒, 静电纺丝, 纳米纤维膜, 光催化性能