Perovskite CaZrO3 for efficient ozonation treatment of organic pollutants in wastewater

Catalytic ozonation with nano-perovskite oxides is a more efficient and advanced oxidation process for the mineralization of organic pollutants. In this study, by regulating the amount of polyethylene glycol during the synthesis of CaZrO3 perovskite-type oxides by the co-precipitation method, efficient surface oxygen vacancies were formed in CaZrO3. Owing to the presence of abundant oxygen vacancies, CaZrO3 modified by PEG exhibited a much higher catalytic activity than unmodified CaZrO3. It was further discovered from the EPR results that the main active oxygen species depend on the surface structure of CaZrO3. The variation of oxygen vacancies on the surface of the catalyst with PEG addition stimulated ozone decomposition to generate a large number of superoxide radicals. This study not only proposed a method to improve the activity of the catalyst, but also further studied the reaction mechanism of CaZrO3 catalyzed ozonation. It provides a solid theoretical basis for the industrial application of catalytic ozonation technology.