Design of a 3D nanowire-CuO/LDH@FeNi-γAl2O3 catalyst and its synergistic mechanism for accelerated dye degradation in wastewater

Abstract

Three-dimensional (3D) particle electrode oxidation technology is an effective advanced oxidation technology for degrading organic pollutants. In this study, a series of γAl₂O₃-supported FeNiCu-layered double hydroxide/CuO composite catalysts (γAl₃O₃ × FNCL@CuO) were synthesized, with the aim of optimizing the electrode preparation process and enhancing the electrocatalytic degradation efficiency for organic dye wastewater. Although γAl₂O₃ itself exhibits relatively low electronic activity, it serves as an effective catalytic support with notable performance-promoting properties, thus representing a valuable subject for investigation. The materials were characterized using X-ray diffraction, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The composite electrode γAl₃O₃ × FNCL@CuO was compared with a pure γAl₂O₃ 3D particle electrode in terms of performance. The results demonstrated that the composite electrode significantly outperformed the pure γAl₂O₃ electrode in pollutant removal and overall electrocatalytic activity. The degradation rates for rhodamine B (RhB), acid yellow (AY), and methylene blue (MB) reached 98.82%, 99.99%, and 98.97%, respectively. Furthermore, comparisons between two-dimensional (2D) and 3D systems revealed that the porous 3D structure facilitates the oxidation process by increasing the contact interface between active sites and reactant molecules. Quenching experiments confirmed that radical scavengers had only a minor inhibitory effect on RhB degradation in the 3D system. In conclusion, γAl₃O₃ × FNCL@CuO shows promising potential for application in the electrochemical treatment of organic wastewater and merits further research.