Abstract As organic dyes are the main pollutants in water pollution, seeking effective removal solutions is urgent for humans and the environment. A novel environmentally friendly three-dimensional CoFe-LDHs (3D CoFe-LDHs) catalyst was synthesized by one-step hydrothermal method. Scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectra, X-ray diffraction, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller technique as well as UV-Vis diffuse reflectance spectra were used to characterize the prepared samples. The experimental results revealed that 3D CoFe-LDHs exhibited a rapid decolorization of methyl orange and Rhodamine B by heterogeneous photo-Fenton process after reaching the adsorption equilibrium, and the final decolorization efficiency reached 91.18% and 93.56%, respectively. On the contrary, the decolorizing effect of 3D CoFe-LDHs on neutral blue was relatively weak. The initial concentrations of azo dyes, pH and H2O2 concentration affected the decolorization of dyes and the catalyst maintained excellent reusability and stability after reuse over five cycles. The quenching experiments found that •OH, •O2− and h+ were the main active substances and reaction mechanisms were further proposed. The study suggests that the synergistic effect of photocatalysis and Fenton oxidation process significantly improved the removal of azo dyes and the synthesized catalyst had potentially promising applications for difficult-to-biodegrade organic pollutants in wastewater.

中文翻译：

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3D花状层状双氢氧化物非均相光芬顿法高效去除偶氮染料的研究

摘要有机染料是水污染的主要污染物，寻求有效的去除解决方案对人类和环境来说都刻不容缓。采用一步水热法合成了一种新型环保三维CoFe-LDHs（3D CoFe-LDHs）催化剂。使用扫描电子显微镜、能量色散光谱、傅里叶变换红外光谱、X射线衍射、X射线光电子能谱、Brunauer-Emmett-Teller技术以及紫外-可见漫反射光谱对制备的样品进行表征。实验结果表明，3D CoFe-LDHs在达到吸附平衡后，通过非均相光芬顿过程对甲基橙和罗丹明B进行快速脱色，最终脱色效率分别达到91.18%和93.56%。相反，3D CoFe-LDHs对中性蓝的脱色效果相对较弱。偶氮染料的初始浓度、pH和H2O2浓度影响染料的脱色，催化剂重复使用5个循环后仍保持良好的重复使用性和稳定性。猝灭实验发现·OH、·O2−和h+是主要活性物质，并进一步提出了反应机理。研究表明，光催化和芬顿氧化过程的协同作用显着提高了偶氮染料的去除率，合成的催化剂对于废水中难以生物降解的有机污染物具有潜在的应用前景。