Perovskite CaZrO3 for efficient ozonation treatment of organic pollutants in wastewater

Abstract

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.