Fe3O4 decorated with α-cyclodextrin for enhanced peroxymonosulfate(PMS)-activated degradation of PPCPs

In this work, novel Fe 3 O 4 @α-CD nanoparticle was synthesized for the catalytic activation of peroxymonosulfate (PMS) towards carbamazepine (CBZ) degradation. The effect of α-CD content, Fe 3 O 4 @α-CD dosage and PMS concentration on the catalyst activity were systematically evaluated. The results showed the synergistic effect between α-CD and Fe 3 O 4 can greatly improve the removal efficiency of CBZ in the Fe 3 O 4 @α-CD/PMS system. CBZ removal efficiency gained 73.37% in 5 min at pH 7.0 with PMS 1 mM, Fe 3 O 4 @α-CD load 0.4 g/L and CBZ 10 μM. The variation in the removal efficiency of different PPCPs under the same conditions mainly ascribed to the adsorption of α-CD and the activation of PMS by Fe 3 O 4 to generate free radicals, in which sulfate radical (SO 4 ·− ) and hydroxyl radicals ( · OH) was determined as the reactive species in the Fe 3 O 4 @α-CD/PMS system. Density functional theory (DFT) calculations was also utilized to optimize the structure of composite and confirmed that the charge distribution mainly concentrate on Fe 3 O 4 . As deduced from the LC-MS analysis, the possible CBZ degradation pathways were proposed. CBZ degradation efficiency still reached 54% after three cycle, which indicates that Fe 3 O 4 @α-CD catalyst has a good reusability potential and practical applications.