Qin Qingdong, Liu Yahong, Li Xuchun, Sun Tian, Xu Yan
School of Civil Engineering, Southeast University Nanjing 210096 China
School of Environmental Science and Engineering, Zhejiang Gongshang University Hangzhou 310018 China.
RSC Adv. 2018 Jan 3;8(2):1071-1077. doi: 10.1039/c7ra12488k. eCollection 2018 Jan 2.
To facilitate rapid dye removal in oxidation processes, copper ferrite (CuFeO) was isothermally reduced in a H flow and used as a magnetically separable catalyst for activation of hydrogen peroxide (HO). The physicochemical properties of the reduced CuFeO were characterized with several techniques, including transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and magnetometry. In the catalytic experiments, reduced CuFeO showed superior catalytic activity compared to raw CuFeO for the removal of methylene blue (MB) due to its relatively high surface area and loading Fe/Cu bimetallic particles. A limited amount of metal ions leached from the reduced CuFeO and these leached ions could act as homogeneous Fenton catalysts in MB degradation. The effects of experimental parameters such as pH, catalyst dosage and HO concentration were investigated. Free radical inhibition experiments and electron spin resonance (ESR) spectroscopy revealed that the main reactive species was hydroxyl radical (˙OH). Moreover, reduced CuFeO could be easily separated by using an external magnet after the reaction and remained good activity after being recycled five times, demonstrating its promising long-term application in the treatment of dye wastewater.
为了促进氧化过程中染料的快速去除，将铁酸铜（CuFeO）在氢气流中进行等温还原，并用作可磁分离的过氧化氢（HO）活化催化剂。采用多种技术对还原后的CuFeO的物理化学性质进行了表征，包括透射电子显微镜、X射线衍射、X射线光电子能谱和磁强计。在催化实验中，还原后的CuFeO由于其相对较高的表面积和负载的铁/铜双金属颗粒，在去除亚甲基蓝（MB）方面表现出比原始CuFeO更高的催化活性。从还原后的CuFeO中浸出的金属离子数量有限，这些浸出离子可作为MB降解中的均相芬顿催化剂。研究了pH值、催化剂用量和HO浓度等实验参数的影响。自由基抑制实验和电子自旋共振（ESR）光谱表明，主要的活性物种是羟基自由基（˙OH）。此外，反应后使用外部磁铁可以轻松分离还原后的CuFeO，并且在循环使用五次后仍保持良好的活性，这表明其在染料废水处理中具有广阔的长期应用前景。
