A recyclable carbon nanofiber/V2O5/g-C3N4 with electron-storage capacity for round-the-clock photocatalytic degradation of tetracycline

The intermittent nature of solar irradiation limits the continuous application of semiconductor photocatalysis. Herein, a recyclable carbon nanofiber/V 2 O 5 /g-C 3 N 4 composite membrane is designed and fabricated through electrospinning and controlled carbonization, integrating photocatalytic function with electron-storage capability. The composite achieves 94.7% tetracycline degradation under light and retains 83.5% efficiency in the dark, surpassing the performance of its powder counterpart. The enhanced activity is attributed to promoted charge separation and the reversible V 5+ /V 4+ redox activity for electron storage. The composite exhibits excellent reusability and structural stability, maintaining high activity over five consecutive cycles without noticeable structural change, outperforming conventional powder catalysts in cycling durability. Mass spectrometry reveals distinct degradation pathways under light and dark conditions. This work provides a stable and easily retrievable membrane material for sustainable, continuous water purification.