Performance and mechanism of efficient activation of peroxymonosulfate by Co-Mn-ZIF derived layered double hydroxide for the degradation of enrofloxacin

Abstract

Due to the uncontrolled synthesis of layered double hydroxides (LDHs), a simple and efficient strategy was needed to construct high-performance LDHs. Herein, Co-Mn-ZIF was used as the sacrificial template to form cobalt-manganese-nickel LDH (M−Co−Mn−Ni LDH) through the process of deconstruction and reconstruction. Due to the sufficient in-situ etching of the Co-Mn-ZIF template, M−Co−Mn−Ni LDH exhibited a larger specific surface area (482.4 m2/g) and pore volume (3.3 × 10−2 cm3/g) as well as easier diffusion and interaction with reaction sites of organic molecules. The prepared M−Co−Mn−Ni LDH showed high catalytic performance for the degradation of enrofloxacin (ENR) by activating peroxymonosulfate (PMS), with the removal rate of 88.5 % within 30 min. The quenching reaction and electron paramagnetic resonance (EPR) analysis results indicated that SO4•− and 1O2 were main active substances in the oxidation process of ENR. In addition, the Co-Mn-Ni LDH/PMS system was stable and almost unaffected by pH values, organic and inorganic substances, and it could achieve high removal efficiency in various pollutant samples. This work provided a convenient and efficient approach for the construction of high-performance MOFs derived LDHs catalysts.