Zn-Fe-CNTs catalytic in situ generation of H2O2 for Fenton-like degradation of sulfamethoxazole

摘要

A novel Fenton-like catalyst (Zn-Fe-CNTs) capable of converting O-2 to H2O2 and further to (OH)-O-center dot was prepared through infiltration fusion method followed by chemical replacement in argon atmosphere. The catalyst was characterized by SEM, EDS, TEM, XRD and XPS. The reaction between Zn-Fe-CNTs and O-2 in aqueous solution could generate H2O2 in situ, which was further transferred to (OH)-O-center dot. The Fenton like degradation of sulfamethoxazole (SMX) using Zn-Fe-CNTs as catalyst was evaluated. The results indicated that Zn-Fe-CNTs had a coral porous structure with a BET area of 51.67 m(2)/g, exhibiting excellent adsorption capacity for SMX, which enhanced its degradation. The particles of Zn-0 and Fe-0/Fe2O3 were observed on the surface of Zn-Fe-CNTs. The mixture of Zn-0 and CNTs could reduce O-2 into H2O2 by micro electrolysis and Fe-0/Fe2O3 could catalyze in-situ generation of H2O2 to produce (OH)-O-center dot through Fenton-like process. When initial pH = 1.5, T = 25 degrees C, O-2 flow rate = 400 mL/min, Zn-Fe-CNTs = 0.6 g/L, SMX = 25 mg/L and reaction time = 10 min, the removal efficiency of SMX and TOC was 100% and 51.3%, respectively. The intermediates were detected and the possible pathway of SMX degradation and the mechanism of Zn-Fe-CNTs/O-2 process were tentatively proposed. (C) 2017 Elsevier B.V. All rights reserved.