Efficient Ofloxacin degradation with Co(II)-doped MoS2 nano-flowers as PMS activator under visible-light irradiation

Base on the strong activation activity and affinity of transition metal ions and MoS2 for peroxymonosulfate (PMS), respectively, Co(II)-doped MoS2 nano-flowers (Co-MoS2 NFs) with a great photo-response property was facilely synthesized to achieve a more efficient PMS activation for ofloxacian (OFX) degradation. It was found that Co-MoS2 NFs exhibits superior catalytic activity for OFX degradation under visible-light irradiation, which was attributed to the synergetic effect of doped Co(II) and photo-generated carriers to PMS activation. Besides, Co-MoS2 NFs was able to efficiently degrade OFX within 4 cycles in the presence of PMS while leaked minute amount of Mo and Co ions, implying the excellent cycle stability of Co-MoS2 NFs. Furthermore, SO4 center dot- and O-1(2) were detected as the primary reactive radicals for OFX degradation in the Co-MoS2 NFs-PMS system through EPR and quenching tests. This new strategy of coupling doped Co(II) and photo-generated carriers for more efficient PMS activation, which will greatly benefit the development of SO4 center dot--based AOPs as well as cater to the demand for environmental remediation in the future.