Nitrogen-rich cobalt metal-organic framework as a heterogeneous catalyst for the degradation of organic dye pollutants in water via peroxymonosulfate activation

Metal organic framework (MOF) materials have attracted widespread interests because of their potential application prospects in the field of heterogeneous catalysis. In this work, a cobalt-based MOF Co3-btca was developed as an efficient heterogeneous catalyst for the degradation of organic dye pollutants in water by activating peroxymonosulfate (PMS). Detailed characterizations showcased that the as-prepared nitrogen-rich Co-MOF Co3-btca possessed micron size and good stability. In the presence of both Co3-btca and PMS, the methyl violet (MV) degradation rate reached 99.78% within 9 min, while the rhodamine B (RhB) degradation rate reached 99.58% within 15 min. The effect of dye concentrations, reaction temperature, PMS and catalyst dosages on degradation reactions was studied. More importantly, successive degradation experiments demonstrated that the as-prepared Co3-btca catalyst possessed good stability with easy recycling for eliminating organic contaminants from wastewater. Radical trapping measurements confirmed that SO4-center dot and (OH)-O-center dot radicals were the main active species for the removal of organic dyes. Moreover, we speculated the possible degradation mechanism of organic dyes. These features make Co3-btca a stable heterogeneous catalyst for the efficient activation of PMS in environmental remediation.