A novel RuO₂@ZnO-Alginate-Halloysite composite for the effective degradation of Eosin Yellow dye and Ciprofloxacin drug

Abstract

This research explores the synthesis and application of a novel RuO₂@ZnO-Alginate-Halloysite composite to effectively mitigate Eosin Yellow (EY) and Ciprofloxacin (CIP). The composite exhibited a predominant zinc oxide (ZnO) phase with added ruthenium oxide (RuO₂), alginate, and halloysite components, confirmed through X-ray diffractogram (XRD), Raman, and Fourier Transform Infrared Spectroscopy (FTIR). The addition of RuO₂ did not alter the crystal structure significantly. Still, it impacted the optical properties, with the band gap energies ranging from 3.281 to 3.252 eV, indicating a redshift associated with increased RuO₂ concentration. The composites were tested for EY and CIP photocatalytic degradation under UV light. The composites containing 2 and 3 % of RuO₂ presented impressive photocatalytic performance, achieving up to 82.53 % degradation of CIP and 68.68 % of EY under UV irradiation respectively, highlighting its potential as a robust solution for environmental remediation. The study employed a series of scavenger tests to identify the primary reactive species involved in the photocatalytic degradation of ciprofloxacin drug and eosin yellow dye. The introduction of benzoquinone led to a significant decrease in photocatalytic activity, indicating that superoxide (•O₂⁻) and hydroxyl radicals (•OH) are the dominant species in the photocatalytic degradation of CIP and EY, respectively. The synergistic effects of these reactive species contribute significantly to the photocatalytic performance of the composite material. Finally, the composites showed good recyclability, maintaining substantial degradation performance over multiple cycles. The significance of this study is underscored by the urgent need to find effective methods for removing hazardous compounds from wastewater, a growing concern due to their harmful impact on aquatic ecosystems and human health.