Unlocking the potential of V₂O₅ decorated on crossed g-C₃N₄ monolayers derived from synergistic bio-transformation of ZnMn₂O₄ for antibiotic photodegradation

Although the physiochemical merits of g-C₃N₄-based photocatalysts have garnered increasing interest in the fields of energy and environmental science, insufficient layer detachment has created a gap between fundamental research and practical applications. To unlock the intrinsic potential of g-C₃N₄, a bio-transformation of the ZnMn₂O₄ ((6)ZM) gel was employed to introduce highly-ordered modulation caused by steric hindrance during melamine pyrolysis. Phytomediated (6)ZM reorganized traditional carbon nitride into crossed C₃N₄ (CCN) monolayers, simultaneously engineering an auspicious Z-schematic system ((6)ZM/CCN). Phytoconverted (6)ZM retained the crystalline-amorphous configuration for facile charge transfer and provided a large surface area (288 m² g⁻¹) that was 2.3 times greater than that of thermally prepared g-C₃N₄ (TCN) monolayers. Additionally, (6)ZM exhibited a quantum confinement-promoted reduction capability and induced bulging on CCN monolayers to fully utilize photons through multilevel light scattering and reflection. Specific sequential two-step calcination of (6)ZM/CCN, furnishing affordable dual Z-schematic VO-(6)ZM/CCN, was specifically developed to introduce a third component into the structure without incurring additional operational cost or complexity. V₂O₅ (VO) nanoparticles were thermally anchored on (6)ZM/CCN to achieve highly efficient levofloxacin (LFC) detoxification under visible-light irradiation. After optimizing all effective synthesis parameters and experimental variables, VO-(6)ZM/CCN exhibited unsurpassed activity, achieving complete LFC photodegradation (50 mg L⁻¹) within 120 min, which was 10.7, 8.7, and 24.7 times more kinetically efficient than the photodegradations achieved by (6)ZM, TCN, and VO, respectively. The outstanding performance of VO-(6)ZM/CCN was evident through complete mineralization of LFC, excellent decontamination of pharmaceutical wastewater within 300 min, resistance to performance deterioration during successive cycling runs, and the corresponding postcharacterization.