Synthesis and Characterisation of Dual Z-Scheme V₂O₅/g-C₃N₄ Photocatalysts for Degrading Ciprofloxacin Antibiotics Under Visible Light

In this research, an innovative Z-scheme vanadium pentoxide (V₂O₅)/graphitic carbon nitride (g-C₃N₄) photocatalyst was synthesised using a facile thermal treatment method, and its photodegradation performance and physicochemical properties were evaluated. The heterostructure provided high Brunauer–Emmett–Teller surface area and pore volume, which encouraged charge carrier separation and transfer, as well as supplied abundant micro-mesoporous structures and active sites for photocatalytic redox reactions. The successful incorporation of V₂O₅ between g-C₃N₄ layers can be proven by proposing the synthesis mechanism, as well as conducting morphology, crystal structure, elemental, and chemical analysis through scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy, respectively. Using these combined photocatalysts, ciprofloxacin (CIP) was successfully degraded up to 90.17% removal efficiency in the visible-light spectrum. The superior photocatalytic activity of g-C₃N₄ composite over V₂O₅ is primarily due to its increased light absorption capacity, as well as increased surface area, pore size, and volume, effective charge transfer, and optimal band alignment between g-C₃N₄ and V₂O₅. This research provides a significant future perspective for the utilisation of Z-scheme V₂O₅/g-C₃N₄ heterojunction photocatalyst for water treatment, especially those involving endocrine-disrupting compounds and antibiotics like CIP.