2D metal–organic framework derived hollow Co/NC carbon sheets for peroxymonosulfate activation

• Hollow Co/NC carbon sheets (HCNSs-9) were synthesized for PMS activation. • The BPA degradation performance and mechanism on HCNSs-9 was investigated. • Significant enhancement of BPA degradation kinetics on HCNSs-9 was observed. • The generated SO4•− was quantified and the degradation mechanism was elucidated. 2D metal–organic frameworks (MOFs) derivatives are a promising kind of heterogeneous catalysts to activate peroxymonosulfate (PMS) but suffer from severe structural collapse during the pyrolysis process. In this work, hollow Co/NC sheets (HCNSs-9) were prepared by pyrolysis of polydopamine (PDA) coated leaf-like Zn/Co zeolite imidazole framework (ZIFs-L@PDA). The bisphenol A (BPA) degradation performance of HCNSs-9 and two samples (ZIFs-L and ZIFs NP@PDA derived carbon) was evaluated and compared. The nitrogen isothermal adsorption and TEM characterization indicated the introduction of PDA can effectively protect the ZIFs-L morphology from collapsing at high temperature and form hollow hierarchical porous structure. When the resultant HCNSs-9 activated PMS to degrade BPA, significantly enhanced degradation performance was achieved. The reaction rate constant ( k ) is 0.341 min −1 , which is 2.3 and 6.1 times higher than that of ZIFs-L derived carbon (ZLC-9) and ZIFs NP@PDA derived carbon (ZNPC-9). Radical quenching experiments and electron paramagnetic resonance (EPR) tests confirmed the sulfate radicals (SO 4 •− ) are the dominant reactive oxygen species for BPA degradation. The residual PMS and generated SO 4 •− in the heterogeneous systems were quantified. Besides, the conversion rate of PMS to SO 4 •− was calculated, and the most suitable catalyst was determined. This work provides an effective and convenient method to synthesize hollow Co/NC sheets with enhanced performance for pollutant degradation.