Magnetic γ-Fe2O3/ZnO@CNTs synthesized by a green precipitation method for the degradation of aniline through photocatalysis coupling catalytic ozonation

Abstract

Aniline is highly toxic and difficult to degrade by conventional biological treatment processes. Thus, more efficient processing technology needs to be developed. Photocatalysis coupling catalytic ozonation (PCO) could be a solution. In this study, a green precipitation method was used to synthesize a γ-Fe2O3/ZnO@CNT catalyst, which exhibits high activity for aniline PCO degradation and strong magnetic properties for rapid separation. Under the optimal conditions, the aniline removal rate reached 93.5%. After 5 reaction cycles, the γ-Fe2O3/ZnO@CNT catalysts can be separated easily with a magnet, and a 91% aniline removal rate can be maintained. Furthermore, there are at least 4 kinds of advanced oxidation processes (AOPs) in this system, i.e., (1) photocatalytic oxidation; (2) catalytic ozonation; (3) photocatalytic ozone; and (4) Fenton oxidation. Thus, a novel stable and magnetically separable catalyst was developed, and new insight were provided for the role of PCO processes in the treatment of aniline.