MOFs-derived magnetic C@Cu-Ni bimetal particles: An efficient peroxymonosulfate activator for 2,4,6-trichlorophenol degradation

In this study, magnetic Cu and Ni bimetallic particles embedded carbon sheets, namely as C@Cu-Ni, was derived via calcining a mixture of Cu-MOFs and Ni-MOFs (mass ratio = 4:6) under N-2 protection and served as a catalyst for the degradation of 2,4,6-trichlorophenol (2,4,6-TCP) by peroxymonosulfate (PMS). The results showed that more than 98.5% of 2,4,6-TCP (10 mg L-1) was rapidly decomposed at initial pH = 5, PMS = 1 mM and catalyst dosage = 0.1 g L-1 within 30 min, accompanied by 42.47% removal of total organic carbon (TOC). This fully confirmed that C@Cu-Ni possessed excellent catalytic performance for PMS activation. The radical quenching experiments and electron paramagnetic resonance (EPR) investigation testified that the reactive oxygen species (ROS) included SO4 center dot-, (OH)-O-center dot, O-2(center dot-) radicals and singlet oxygen (O-1(2)), which were responsible for the rapid degradation of 2,4,6-TCP. Among them, O-2(center dot-) and O-1(2) played a decisive role. Cyclic voltammograms (CV) and electrochemical impedance spectroscopy (EIS) revealed that C@Cu-Ni material possessed superior electrical conductivity and electron transfer, improving its catalytic activity. What is more, C@CueNi displayed excellent stability and could be consecutively used for five times without any decline of catalytic performance. The main intermediates of the 2,4,6-TCP degradation were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) and possible pathways of 2,4,6-TCP degradation were further proposed. The extraordinary stability and superior catalytic activity of C@Cu-Ni coupled with its easy separation from wastewater due to magnetism suggest that the newly synthesized material may offer a promising alternative approach to efficiently degrade organic pollutants by PMS. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

In this study, magnetic Cu and Ni bimetallic particles embedded carbon sheets (C@Cu-Ni) were synthesized and shown to have excellent catalytic performance for the degradation of 2,4,6-trichlorophenol by peroxymonosulfate. The material exhibited good stability, superior electrical conductivity, and could be consecutively used for five times without decline in catalytic performance. The main intermediates of the degradation were analyzed and possible pathways were proposed, suggesting a promising alternative approach for efficient degradation of organic pollutants.