Enhanced Ultrasonic-Assisted Heterogeneous Fenton Degradation of Organic Pollutants over a New Copper Magnetite (Cu-Fe3O4/Cu/C) Nanohybrid Catalyst

Abstract

A copper magnetite nanohybrid catalyst (Cu-Fe3O4/Cu/C), abundant of Schottky interfaces and structural defects, with ultrathin encapsulation of graphitic carbon, was synthesized and tested. The catalyst shows enhanced catalytic activity, far higher than the single and mixed counterparts toward ultrasonic-assisted heterogeneous Fenton degradation of rhodamine-B, exhibiting a reaction rate constant of 0.146 min-1 much larger than that over carbon-encapsulated Cu (Cu/C, 0.010 min-1) and over Fe3O4 (Fe3O4/C, 0.009 min-1). Besides, the catalyst also delivers good reusability, showing less than 7% decrease of removal efficiency even after four cycles. As evidenced by the electron paramagnetic resonance spectra and high-resolution transmission electron microscopy, the Schottky interface between Cu and Fe3O4 endows the catalyst with a good electron donor feature and significantly boosts the formation of ·OH and ·O2- radicals, and the conductive encapsulation layer and the abundant structural defects accelerate charge-transfer process in Fe3O4, which together contribute to the impressive increase of the degradation rate. © 2020 American Chemical Society.