Effective activation of peroxonosulfate by CO32 − intercalated Ni-doped CoMn-LDH nanoparticles for phenol degradation: Catalytic performance and mechanism studies

In this study, CO 3 2− intercalated Ni-doped CoMn layered double hydroxides were synthesized by co-precipitation method and used as peroxonosulfate (PMS) activation to degrade phenol efficiently. The physical and chemical properties of the catalyst were characterized by a series of methods. The effects of catalyst dosage, PMS concentration and initial pH value on phenol removal rate were investigated. The degradation mechanism was investigated by electron paramagnetic resonance (EPR) and quenching experiments. Experimental results indicated that the phenol removal is significantly impacted by the sulfate radical (SO 4 •− ), superoxide anion (O 2 •− ) and singlet oxygen ( 1 O 2 ). Furthermore, the inclusion of Ni stimulates the REDOX cycle of Co and Mn, and the activation of PMS to form active free radicals is caused by the REDOX cycle of Co 2+ /Co 3+ , Mn 2+ /Mn 3+ /Mn 4+ , Ni 2+ /Ni 3+ .