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

Abstract

AbstractBACKGROUNDVanadium‐doped manganese dioxide (V‐MnO2) was fabricated for effective photocatalytic degradation of ciprofloxacin (CIP) and moxifloxacin (MOXI) antibiotics under visible light. V‐MnO2 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.RESULTSDLS measured average particles size of 93.18 nm for MnO2, which reduced to 88 nm for V‐ MnO2 and zeta potential indicated −11.5 mV for MnO2 and 17.7 mV for 1% V‐MnO2. PL spectra of V‐MnO2 was suppressed as compared to MnO2 spectra, indicating a decrease in electron hole recombination and leading to increased photocatalytic activity of V‐MnO2. Band gap results revealed a successful decrease in band gap of MnO2 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‐MnO2 catalyst was recyclable for three cycles.CONCLUSIONV‐MnO2 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, MnO2 and V‐MnO2 were built and optimized. Total energy values measured by a semi‐empirical method revealed that V‐MnO2 structure was less stable than MnO2, with weakened bonds between Mn atoms of MnO2 structure after doping of V ions. © 2022 Society of Chemical Industry (SCI).