He Hongping, Liu Ying, Wu Deli, Guan Xiaohong, Zhang Yalei
State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science & Engineering, Tongji University, Shanghai 200092, PR China.
State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science & Engineering, Tongji University, Shanghai 200092, PR China.
Environ Pollut. 2017 Aug;227:73-82. doi: 10.1016/j.envpol.2017.04.065. Epub 2017 Apr 28.
Heterogeneous catalytic ozonation provides a promising alternative in the degradation of recalcitrant contaminants. CuO-FeO nanoparticles (CuFeO 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/CuFeO was significantly faster than those ozonation catalyzed by CuO, FeO, or mixture of CuO and FeO (1:1 M ratio), which was ascribed to the unique CuFeO NPs that composed of abundant structural Cu(I) (≡Cu(I)). It was among the first revealing the synergistic effect between ≡Cu(I) and surface lattice oxygen (O) in HO· generation, resulting in rapid DMP degradation kinetics and high mineralization efficiency. Besides the generation of ≡Cu(I), 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(I) 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 low-valent 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.
非均相催化臭氧化为难降解污染物的降解提供了一种有前景的替代方法。以Fe(0)为前驱体创造性地合成了含有Cu(I)和Cu(II)的CuO-FeO纳米颗粒（CuFeO NPs，粒径约70 nm），并将其用作邻苯二甲酸二甲酯（DMP）降解的臭氧化催化剂。结果表明，O/CuFeO对DMP的降解速度明显快于CuO、FeO或CuO与FeO混合物（1:1摩尔比）催化的臭氧化反应，这归因于由大量结构Cu(I)（≡Cu(I)）组成的独特CuFeO NPs。这是首次揭示≡Cu(I)与表面晶格氧（O）在羟基自由基（HO·）生成过程中的协同作用，从而导致快速的DMP降解动力学和高矿化效率。除了生成≡Cu(I)外，Fe(0)与Cu(II)之间的电偶腐蚀还生成了结构Fe(II)，其可将≡Cu(II)还原回≡Cu(I)，从而补偿≡Cu(I)的电子损失，最终在≡Cu(II)和≡Cu(I)之间实现高效循环。基于检测到的中间产物介绍了DMP的降解途径。通过调节低价金属（≡Cu(I)）的（再）生成，本研究提供了一种创新策略，可显著促进催化臭氧化过程中HO·的生成，这可能为高级废水处理带来希望。
