Revolutionizing photocatalysis: a rationally designed double Z-scheme nanohybrid for fast and efficient antibiotic detoxification

A novel ternary composite, TiO₂/CeMnO₃/g-C₃N₄, featuring a double Z-scheme assembly, was synthesized via integrated approaches for the visible-light-driven degradation of levofloxacin (LVF) in contaminated water. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HR-TEM), and energy-dispersive X-ray spectroscopy (EDX) were employed to methodically analyze the crystalline structure, morphology, and elemental composition of the synthesized materials. The composite's photocatalytic potential was examined through ultraviolet–visible (UV–Vis) absorption spectroscopy, Brunauer–Emmett–Teller (BET) surface area analysis, photoluminescence (PL) spectroscopy, and transient photocurrent response measurements. Levofloxacin degradation was conducted under visible light irradiation with a 150-watt Philips CFL lamp to further assess its photocatalytic activity. The ternary photocatalyst demonstrated an impressive 98.5 % degradation of levofloxacin (LVF) in a mere 50 min under visible light irradiation (150 W Philips CFL), adhering to a pseudo-first-order kinetic model characterized by a rate constant of 0.0201 min⁻¹. Furthermore, the composite maintained an impressive 95.2 % degradation efficiency following five cycles of reuse and exhibited remarkable structural stability during the reusability assessments. At neutral pH, 24 mg/L LVF concentration, and 0.4 mg/L catalyst dosage, optimal performance was observed. The proposed double Z-scheme mechanism received validation from radical scavenging studies, which identified ^●O₂⁻ and ^●OH as the primary reactive species involved. The results demonstrate the efficacy, stability, and reusability of the composite in addressing wastewater contaminated with antibiotics.