In situ N-doped carbon-coated mulberry-like cobalt manganese oxide boosting for visible light driving photocatalytic degradation of pharmaceutical pollutants

Efficient activation of peroxymonosulfate (PMS) is a desirable strategy to generate sulfate radicals for degradation of organic contaminants. Herein, in situ N-doped carbon-coated mulberry-like cobalt manganese oxide (H-CoMnOx@NC) are prepared, and utilized as photo-Fenton-like catalyst versatile for the removal of seven typical pharmaceutical active compounds (PhACs), i.e., sulfamethazine (SMZ), sulfasalazine (SSZ), tetracycline (TC), norfloxacin (NOR), carbamazepine (CBZ), metronidazole (MNZ), and amoxicillin (AMX). For example, the H-450CoMnO(x)@NC manifests the extraordinary catalytic property for activating PMS, with almost perfect degradation of SSZ, CBZ, MNZ and AMX in 30 min of visible light irradiation. Meanwhile, SMZ (95.4%), TC (88.9%) and NOR (79.2%) can also be efficiently eliminated using the same system. The combination of the inherent merits of bimetallic oxide core with N-doped carbon shell is able to realize the accelerating mass transfer, facilitating photoinduced carriers separation, boosting light absorption capacity, preventing metal ions leaching, and offering adequate active centers, which are all beneficial for improving catalytic performance. Besides, the reactive oxygen species, the decomposition pathways of PhACs, and the synergetic degradation mechanism are investigated systematically. Findings from this study may shed light on the design of catalytically active bimetallic oxides as robust photo-Fenton-like catalysts with a promising practical utilization value.

Automated summary

The efficient activation of peroxymonosulfate (PMS) is crucial for generating sulfate radicals to degrade organic contaminants. In this study, in situ N-doped carbon-coated mulberry-like cobalt manganese oxide (H-CoMnOx@NC) was prepared and used as a versatile photo-Fenton-like catalyst for the removal of seven typical pharmaceutical active compounds. The bimetallic oxide core combined with N-doped carbon shell showed excellent catalytic performance, facilitating mass transfer, carriers separation, light absorption, preventing metal leaching, and providing active centers.