Surface-Floating Polyvinylidene Fluoride (PVDF) Bead Photocatalysts with V₂O₅/g-C₃N₄ for Enhanced Ciprofloxacin Degradation

Vanadium pentoxide/graphitic carbon nitride (V₂O₅/g-C₃N₄) photocatalyst has attracted considerable attention for the degradation of organic pollutants in wastewater via advanced oxidation processes. However, its powdered form suffers from poor recoverability, potential secondary pollution, and material loss, which limit practical application. In this work, a floating photocatalytic bead system was developed by immobilizing V₂O₅/g-C₃N₄ onto a polyvinylidene fluoride (PVDF) matrix via a phase inversion technique, forming VCBs (V₂O₅/g-C₃N₄-PVDF beads). The engineered beads exhibit a hierarchical porous structure and self-floating capability, enabling efficient light harvesting at the air–water interface while enhancing the accessibility of ciprofloxacin (CIP) molecules to active sites through improved surface interaction and diffusion pathways. This structural advantage significantly enhances photocatalytic performance under visible light irradiation (100 W LED). Under the best performing conditions (pH 7, catalyst dosage 1.0 g/L, and initial CIP concentration 10 ppm), the VCB system achieved 89.2% CIP degradation. The beads also demonstrated excellent stability, maintaining high photocatalytic activity over six consecutive cycles with less than 25% performance loss. In addition, the immobilized configuration facilitates easy recovery and reduces catalyst loss, addressing key limitations of conventional powder photocatalysts. Overall, this study presents a durable, efficient, and reusable floating photocatalyst system that integrates structural engineering and heterojunction design, offering a promising strategy for sustainable antibiotic removal in wastewater treatment applications.