Ozonation of dimethyl phthalate catalyzed by highly active Cux-Fe3O4 nanoparticles prepared with zero-valent iron as the innovative precursor

Heterogeneous catalytic ozonation provides a promising alternative in the degradation of recalcitrant contaminants. CuxO-Fe3O4 nanoparticles (CuxFeO NPs, both Cu(I) and Cu(II) were contained, about 70 nm) were creatively synthesized using Fe(0) as the precursor and subsequently employed as the ozonation catalyst for dimethyl phthalate (DMP) degradation. Results showed that DMP degradation by O-3/CuxFeO was significantly faster than those ozonation catalyzed by CuO, Fe3O4, or mixture of CuO and Fe3O4 (1:1 NI ratio), which was ascribed to the unique CuxFeO NPs that composed of abundant structural Cu(l) ( Cu(I)). It was among the first revealing the synergistic effect between Cu(I) and surface lattice oxygen (O2-) in HO. generation, resulting in rapid DMP degradation kinetics and high mineralization efficiency. Besides the generation of Cu(l), galvanic corrosion between Fe(0) and Cu(II) also generated structural Fe(II), which could reduce the Cu(II) back to Cu(I), thus compensating the electron loss of Cu(l) and finally obtaining a high-efficiency cycling between Cu(II) and Cu(I). The DMP degradation pathway was introduced based on the intermediates detected. By regulating the (re)-generation of lowvalent metal ( Cu(I)), this study provides an innovative strategy to significantly promote the generation of HO. in catalytic ozonation, which might be promising for advanced wastewater treatment. (C) 2017 Elsevier Ltd. All rights reserved.