Mesoporous bouquet-like Co 3 O 4 nanostructure for the effective heterogeneous activation of peroxymonosulfate

A facile hydrothermal and subsequent calcination method is proposed for the synthesis of mesoporous bouquet-like Co3O4 nanostructure. The prepared Co3O4 nanostructure is efficient for the activation of peroxymonosulfate (PMS). Morphological observation clearly indicates that the micron-scale bouquet-like structure is composed of numerous regular Co3O4 nano-rods. X-ray diffraction (XRD), X-ray photo-electron spectroscopy (XPS), and fourier transform infrared spectroscopy (FTIR) spectra indicate the high purity and crystallinity of the prepared Co3O4 nanostructure. The N2 adsorption-desorption isotherm analysis shows that the bouquet-like Co3O4 nanostructure possesses a moderate specific surface area (37.0 mg−2) and mesoporous property. The fluoroquinolone antibiotics (nofloxacin, NOR and ofloxacin, OFX) can be effectively degraded in the Co3O4/PMS oxidation system under ambient conditions. In addition, the extremely low metal leaching (no more than 0.07%) indicates that the heterogeneous activation mechanism plays a much significant role in the activation process. By using the radical scavengers, the sulfate radical is found to be the dominant oxidative species in the degradation process. These results reveal that the designed Co3O4 nanostructure exhibit promising capability for the environmental remediation.