Enhancing metronidazole photodegradation through the application of dysprosium vanadate/oxidized carbon nanofiber composite

The widespread usage of nitroimidazole antibiotics, including metronidazole (MD), and the improper disposal of pharmaceutical residues in groundwater samples pose a significant health risk due to the potential carcinogenic and mutagenic toxicity. Our research engineered a nanocomposite by combining dysprosium vanadate with oxidized carbon nanofibers (DyVO4/O-CNF) through coprecipitation, acid treatment, and ultrasonication methods. We meticulously examined these prepared nanocomposites using various spectroscopic and microscopic techniques, revealing enhanced characteristics in crystallinity, active vibrational bands, valence states, band gap, and structural morphology. To assess the photocatalytic efficacy of DyVO4/O-CNF nanocomposite for degrading MD, we performed a series of photocatalytic experiments. These included optimizing the dosage, analyzing MD concentration, studying the influence of radical scavengers, and examining the mineralization process along with the potential photodegradation mechanism. Our findings demonstrated that the DyVO4/O-CNF nanocomposite (98.7 % within 40 min) surpassed other catalysts such as TiO2 (26.1 %), pristine CNF (40.3 %), and DyVO4 (59.6 %). Furthermore, we evaluated the nanocomposite's stability and reusability, revealing a consistent photodegradation efficiency of 94.7 % even after five consecutive cycles. These findings highlight the efficacy of the DyVO4/O-CNF nanocomposite as a highly effective catalyst for the photodegradation of MD.