Preparation of Co/Cu-based bi-MOFs and the degradation of sulfamethoxazole by activated peracetic acid

Abstract

Compared with the common synthesis methods of metal-organic frameworks (MOFs), Co/Cu-based bi-MOFs composite catalyst CoXCu(10-X)-MOFs (X ¼ 2, 4, 6, and 8) was prepared by a facile synthesis method at room temperature. The bi-MOFs composite catalyst was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The removal ability of sulfamethoxazole (SMX) by different Co:Cu rate bi-MOFs composite catalysts, single Co-based MOFs (zeolitic imidazolate framework-67, ZIF-67), and Cu-based MOFs (Hong Kong University of Science and Technology-1, HKUST-1) were investigated and the effects of peracetic acid (PAA) concentration, catalyst dosage, the common interfering substances (Cl-, HCO3-, SO42-, HA) in water, and SMX removal were investigated. Through the analysis of different free radical scavengers and the changes of surface elements before and after the reaction, the oxidation mechanism was further explored, and the stability of Co4Cu6-MOFs was explored through repeated recycling. The experimental results demonstrate that Co4Cu6-MOFs have a high catalytic activity for PAA. Co4Cu6-MOFs/PAA show the best removal effect of SMX under neutral conditions and the presence of Cl- and HCO3- can promote the removal of SMX.