Green electrochemical fabrication of WO3 nanostructures using Cistus extracts for enhanced photoelectrocatalytic degradation of ciprofloxacin

The development of sustainable fabrication routes for advanced semiconductor materials is crucial for environmental technology. This work presents a green electrochemical anodization strategy to fabricate tungsten trioxide (WO3) nanostructures, employing aqueous extracts of two Mediterranean plants, Cistus monspeliensis and Cistus albidus, as environmentally benign electrolytes. Nanostructures synthesized with varying extract percentages were comprehensively characterized by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and electrochemical impedance spectroscopy measurements. Their performance was evaluated in photoelectrocatalytic (PEC) tests under simulated sunlight. The WO3 nanostructures anodized in the presence of optimal concentrations (7%) of C. monspeliensis and C. albidus extracts demonstrated superior properties. These optimal samples were then applied to degrade ciprofloxacin, a persistent antibiotic pollutant. The C. albidus-derived photoelectrocatalyst exhibited markedly higher efficiency, achieving a degradation rate constant of 1.76 h−1, which is four times faster than the 0.43 h−1 constant obtained for the C. monspeliensis-based sample. This study confirms that plant extracts can effectively tune the properties of anodized WO3 and introduces Cistus albidus extract as a particularly effective green agent for fabricating high-performance PEC materials for the removal of emerging water pollutants, using a green fabrication process to create high-performance materials for environmental cleanup.