Enhanced PMS Activation by Highly Dispersed Mn-Ce Bimetallic Oxide on Carbon Nanotubes for Degradation of Phenol

Abstract

Peroxymonosulfate (PMS) activation is an intriguing technology for refractory organic pollutant removal in wastewater treatment. Herein, a highly dispersed Mn-Ce bimetallic oxide on carbon nanotubes (MCC) was synthesized and applied to catalyze PMS for the degradation of phenol. The material was well characterized using a transmission electron microscope (TEM), N2 adsorption–desorption isotherms, X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The synthesized MCC showed superior activity for PMS activation. The k value of phenol removal with MCC is 0.135 min−1, which is greatly superior to that of CNT (6.17 × 10−5 min−1) and Mn-Ce bimetallic oxide (3.18 × 10−4 min−1). Electron paramagnetic resonance (EPR), along with radical quenching experiments, revealed that the activation of PMS by MCC for phenol degradation involves both radical and non-radical reaction pathways. Moreover, a synergic effect between Mn-Ce bimetallic oxide and CNT was identified to be responsible for the outstanding catalytic activity.