异相类Fenton催化剂CuFeO2的制备及其对水中氧氟沙星的降解性能

以三水合硝酸铜、九水合硝酸铁分别作为铜源和铁源，通过简单的一步水热法合成纯3R相结构CuFeO₂催化剂。通过X射线衍射仪、扫描电镜、透射电镜和高分辨透射电镜对其晶格结构和形貌进行了表征，构建了CuFeO₂/H₂O₂体系对目标污染物氧氟沙星(OFX)进行降解，考察了不同催化剂投加量、H₂O₂浓度、溶液pH等参数对OFX降解效果的影响。结果表明，在催化剂投加量为1.1 g ·L⁻¹、H₂O₂浓度为15 moL·L⁻¹以及pH=3.65的条件下，反应300 min后，CuFeO₂/H₂O₂体系对10 mg·L⁻¹ OFX的降解率高达93.8%；此外，CuFeO₂催化剂在活化H₂O₂降解OFX过程中具有良好的稳定性，经5次降解后的降解率仅降低了8.1%；自由基捕获实验和电子自旋共振波谱测试结果表明CuFeO₂/H₂O₂体系中·OH是主要的活性自由基；降解反应前后CuFeO₂的X射线光电子能谱表征结果表明，Cu⁺和Fe³⁺的相对含量均有不同程度的降低，表明CuFeO₂中的Fe和Cu双活性位点在异相类Fenton反应中均起着重要的作用。最后，通过质谱鉴定了OFX的降解产物，并在此基础上提出了可能的降解路径。

Preparation of CuFeO2 as heterogeneous Fenton-like catalyst and its degradation performance on ofloxacin in the water

The CuFeO2 catalyst with pure 3R phase structure was synthesized via a simple one-step hydrothermal method using copper nitrate trihydrate and iron nitrate as copper and iron sources, respectively. The lattice structure and morphology were characterized by X-ray diffractometer, scanning electron microscopy, transmission electron microscopy and high-resolution transmission electron microscopy. The CuFeO2/H2O2 system was constructed for the degradation of ofloxacin (OFX) as the target pollutant. To explore the optimum operating parameters, the effects of catalyst dosage, H2O2 concentrations, solution pH values and coexistence ion on OFX degradation were discussed. The results showed that the degradation efficiency of OFX (10 mg·L−1) by CuFeO2/H2O2 system was 93.8% after 300 min at catalyst dosage of 1.1 g·L−1, H2O2 concentration of 15 moL·L−1 and pH=3.65. In addition, the prepared CuFeO2 catalyst exhibited good stability, and the degradation efficiency after five successive degradation cycles only decreased by 8.1%. Based on the free radical scavenging experiments and electron spin resonance spectrometer results, ·OH was the major active free radicals in CuFeO2/H2O2 system for OFX degradation. The X-ray Photoelectron Spectrometer spectra of CuFeO2 before and after the degradation reaction revealed that the relative contents of Cu+ and Fe3+ decreased in varying degrees, indicating that the Fe and Cu as the double catalytic active sites in CuFeO2 played an important role in the heterogeneous Fenton-like reaction. A possible degradation pathway of OFX was proposed based on the intermediates identified by HPLC-MS spectra.