Vanadium‐doped MnO2 nanocatalyst for visible‐light‐driven photodegradation of selected fluoroquinolone antibiotics from contaminated water

Abstract BACKGROUND Vanadium‐doped manganese dioxide (V‐MnO 2 ) was fabricated for effective photocatalytic degradation of ciprofloxacin (CIP) and moxifloxacin (MOXI) antibiotics under visible light. V‐MnO 2 fabricated by simple redox method was characterized by spectrophotometry, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, zeta potential, dynamic light scattering (DLS), Fourier transform infrared spectroscopy and photoluminescence (PL) techniques. RESULTS DLS measured average particles size of 93.18 nm for MnO 2 , which reduced to 88 nm for V‐ MnO 2 and zeta potential indicated −11.5 mV for MnO 2 and 17.7 mV for 1% V‐MnO 2 . PL spectra of V‐MnO 2 was suppressed as compared to MnO 2 spectra, indicating a decrease in electron hole recombination and leading to increased photocatalytic activity of V‐MnO 2 . Band gap results revealed a successful decrease in band gap of MnO 2 from 3.30 to 2.82 eV after doping with 1% V. Maximum degradation of CIP and MOXI achieved was 92% ± 2.98% and 79.5% ±2.15%, respectively, at pH 6. Optimum visible light irradiation of 180 and 300 min was calculated for CIP and MOXI, respectively. V‐MnO 2 catalyst was recyclable for three cycles. CONCLUSION V‐MnO 2 catalyst was successfully applied to treatment of CIP and MOXI in spiked real water supply and sewage wastewater samples. Computational molecular models of CIP, MOXI, MnO 2 and V‐MnO 2 were built and optimized. Total energy values measured by a semi‐empirical method revealed that V‐MnO 2 structure was less stable than MnO 2 , with weakened bonds between Mn atoms of MnO 2 structure after doping of V ions. © 2022 Society of Chemical Industry (SCI).