Fe-based metallic glass ribbons as dual electrodes for ultrasonic cavitation-enhanced electro-Fenton degradation of ofloxacin

Abstract

Electrochemical degradation holds significant promise for wastewater treatment. This study introduces an ultrasonic cavitation-enhanced electrochemical degradation system that employs Fe-Si-B metallic glass ribbons as both cathodic and anodic materials for the degradation of ofloxacin (OFL) in wastewater. Under acidic conditions (pH = 3) with a 25 mA applied current, the system achieves a good degradation efficiency (98.4%) for 25 mg/L OFL within 30 min. The OFL removal efficiency increases with rising current. Anodic oxidation induces the formation of cluster-like oxidized structures on the ribbon surface, which enhances the hydrophilicity of the electrodes. Ultrasonication further promotes the development of these clustered morphologies and improves the electrodes’ hydrophilicity. Moreover, ultrasonic assistance boosts degradation performance, particularly during the initial reaction stage by increasing the removal efficiency from 33.4% to 61.5% within the first 15 min. It also enhances the mineralization efficiency 3-fold (from 12.1% to 36.3%) and raises the reaction rate constant by 1.52 times (from 0.02361 min^-1 to 0.03587 min^-1). Hydroxyl radicals and hydrogen radicals are identified as the dominant reactive species involved in the degradation mechanism. After 10 reuse cycles, the Fe-based amorphous ribbon maintained a degradation rate of nearly 90%, highlighting its remarkable stability. This work provides an efficient and robust strategy for antibiotic wastewater treatment and highlights the potential of amorphous materials for advanced oxidation processes.