Zn-MOF-C Catalyzed Ozonation of Ibuprofen: Performance and Catalytic Mechanism
摘要
ZIF-8-derived materials showed great potential for adsorbing and decomposing ozone, making them suitable for application in catalytic ozonation. This study synthesized four X-Zn-MOF-C (X = 4, 6, 8, 10) materials, among which 10-Zn-MOF-C exhibited the best catalytic performance, possibly due to its superior promotion of ozone decomposition into ∙OH. A probe method was employed to quantify ROS (∙OH, O2−· and 1O2) in the four X-Zn-MOF-C/O3 systems. The results showed that the yield of ∙OH was lower than that of O2−· and 1O2, however, ∙OH played a more critical role in IBP degradation. ROS quenching experiments further confirmed the significant contribution of ∙OH to pollutant removal. Further the investigation into the sources of ∙OH generation was conducted from two dimensions, catalyst sites and solution properties. Compared to the surface hydroxyl protonation of the catalyst, the synergistic effect between the exposed Zn2+ and oxygen vacancy on the catalyst surface was more favorable for ∙OH generation on the catalyst surface, which mainly resulted from the formations of metal and vacancy hydroxyl groups. Meanwhile, the generation of ∙OH in the solution relied on the contribution of H2O2 produced from pollutant degradation.