Fe doped CeO2 nanocubes with the exposure of active (100) facets for photocatalytic ozonation of 4-chlorophenol under solar irradiation

BACKGROUND To strengthen the treatment efficiency of photocatalytic ozonation, it is necessary to develop a stable bifunctional catalyst active in both processes of photocatalysis and catalytic ozonation. RESULTS A series of Fe doped CeO 2 nanocubes with the main exposure of active (100) crystal facets were simply synthesized by a one-pot hydrothermal method and applied in photocatalytic ozonation for the first time. It was found that doping did not change the morphology of nanocubes but it decreased the crystal size, induced abundant defects of oxygen vacancies and Ce 3+ , and shifted the optical absorption edge to the visible region. Due to these structure modifications, Fe doped CeO 2 nanocubes enhanced the mineralization rate of 4-chlorophenol by 55.4–74.7% and reduced the formation of carcinogenic bromate by 60.2–85.4%, depending on the doping content. Due to the simultaneous occurrence of photocatalysis, catalytic ozonation, and their synergy in 5%Fe-CeO 2 mediated photocatalytic ozonation under solar irradiation, 4-chlorophenol almost completely degraded within 9 min, 74.7% of mineralization rate was achieved within 45 min, and the first order kinetics reaction constant reached 2.97 × 10 −2 ·min −1 , about 4.1 times that of photo ozonation without any catalysts. Moreover, the introduction of 5%Fe-CeO 2 to the ozonation, photolysis, and photo ozonation decreased the corresponding energy consumption by 60.2%, 84.2%, and 62.5%, respectively. CONCLUSION In this study, an efficient and economical Fe doped CeO 2 nanocubes-mediated photocatalytic ozonation process was successfully developed for the refractory organics-containing wastewater treatment under solar light irradiation. © 2021 Society of Chemical Industry