Synthesis of bimetallic NbCo-piperazine catalyst and study on its advanced redox treatment of pharmaceuticals and personal care products by activation of permonosulfate

Here, a nano disc-shaped bimetallic organic framework (NbCo-piperazine) was prepared by the solvothermal method for the activation of PMS for the degradation of contaminants. The effects of Nb/Co ratio, synthesis time and temperature on the morphology, structure and performance of the NbCo-piperazine catalyst were characterized by XRD, FT-IR, SEM-EDS and TEM. The optimum conditions for NbCo-PZ to activate PMS degradation of tetracycline were investigated by adjusting the dosage of catalyst, tetracycline concentration, pH and PMS concentration. The catalytic performance of NbCo-PZ in the presence of co-existing anions (Cl − , NO 3 – , HCO 3 2– , H 2 PO 4 − ) was also evaluated. XPS explained that cyclic changes in the valence states of Nb 4+ /Nb 5+ and Co 2+ /Co 3+ accelerated the activation of the PMS degradation process. EPR results showed the presence of free radicals (SO 4 ·− , ·OH and O 2 ·− ) and non-free radicals ( 1 O 2 ) in the degradation process, with free radicals playing a major role in the degradation process. The degradation rate of tetracycline after three cycles was 92.2%. In addition, NbCo-piperazine showed good catalytic performance for other organic pollutants such as methyl blue, tylosin tartrate and tetracycline with the degradation rate of 97.8%, 95.2% and 95.5%, respectively. Moreover, it also has good catalytic properties in various water systems such as river water and sea water.