Enhanced 2, 4-dichlorophenol degradation at pH 3–11 by peroxymonosulfate via controlling the reactive oxygen species over Ce substituted 3D Mn2O3

Abstract Peroxymonosulfate (PMS) activation has drawn increasing attention in eliminating the recalcitrant organic pollutants in water. Manipulation of generated reactive oxygen species (ROS) over Ce doped Mn 2 O 3 during the PMS activation was firstly reported for the complete degradation of 2,4-dichlorophenol (2,4-DCP) in this study. Ce in-situ introduction can greatly enhance the PMS activation performance of Mn 2 O 3 . For example, 100% of 2,4-DCP degradation can be obtained at 90 min over 4 wt% Ce doped Mn 2 O 3 at pH 7 (82.1% for Mn 2 O 3 at 90 min). The reaction rate constant ( k ) was also about 3.6 times higher than that of Mn 2 O 3 (0.0668 min −1 for Ce doped Mn 2 O 3 vs. 0.0186 min −1 for Mn 2 O 3 ). Besides 1 O 2 , OH and SO 4 − were identified and involved in 2,4-DCP degradation process over Ce doped Mn 2 O 3 , while only 1 O 2 was detected over 3D Mn 2 O 3 . Moreover, the contribution of OH and SO 4 − to 2,4-DCP degradation can be regulated by adjusting the Ce doping amount. The key role of Ce substitution in the regulation of reactive oxygen species was further investigated by XPS and electrochemical experiments. The Ce dopant can lead to a higher current density and greater reductive capability due to the improved charge transfer capability, which is important to the generation of more aggressive OH and SO 4 − and complete 2,4-DCP degradation.