Synthesis of ZIF-derived C-doping Co3O4/ ZnO membranes for enhanced removal of organics by peroxymonosulfate activation under visible-light

The technology that catalyst activated perxymosulfate (PMS) has been widely used in the decomposition of organic pollutants. We prepared Zn and Co-based ZIF and obtained C-doping Co 3 O 4 / ZnO heterojunction after pyrolysis. C-doping Co 3 O 4 / ZnO heterojunction with cage core-shell structure was loaded on the polyvinylidene fluoride (PVDF) membranes with a layered porous structure by solvent-assisted nanoparticle embedding (SANE) method, where the carmine degradation reached 99.6 % by MC-430 activated Perxymosulfate (PMS) within 10 min. The influencing factors (such as the pyrolysis temperature, PMS dosage, and dye concentration) on OFX degradation were observed, and MC-430 exhibited good tolerance for these factors and a wide range of solution hydrogen ion concentrations (pH= 4–10). The strong reusability and stability analysis showed that the carmine degradation of the MC-430/PMS system changed minorly (from 99.6 % to 97.7 %) in 5 consecutive cycles without any treatment. The degradation mechanism was confirmed by capture experiments, in which the non-free radical path was the main one and the free radical path was the auxiliary one. Moreover, structure characterizations and density functional theory calculations verified that doped C sites provided a channel for electron transfer from Zn sites to Co sites, which increased the generation rate of reactive oxygen species (ROS) and prolonged the catalyst life. This work provides a new method for the preparation of nonmetallic doping bimetallic strong coupling catalysis.