The strong promoting effects of thin layer Al₂O₃ on FeCu Fenton-like components: Enhanced electron transfer

The Fe(III)/Fe(II) redox cycle is the main factor limiting the effectiveness of Fe-mediated advanced oxidation processes (AOPs) for the degradation of organic pollutants. In this study, the promoting effects of thin-layer Al₂O₃ (t-Al₂O₃) between the frequently used FeCu components and the mesoporous silica support were studied to reduce Fe(III) to promote the activity of the Fenton-like catalyst. After modification by t-Al₂O₃, the mesoporous silicon-loaded FeCu catalyst removed 97% of Rhodamine B at pH 7, which was superior to the unmodified sample with a removal rate of 62.4% under the same conditions. Morphological characterization and X-ray diffraction patterns indicated that the Fe-Cu/t-Al₂O₃ active components were highly dispersed. Pyridine infrared spectra suggested that all of the acid sites were Lewis acids, and the t-Al₂O₃-loaded samples provided moderate/strong Lewis acids. The loading of t-Al₂O₃ between the FeCu complex and mesoporous silica support facilitated electron transfer during the Fe(III)/Fe(II) redox cycle by enhancing the dispersion of Fe-Cu/t-Al₂O₃ and the Lewis acidity. The results of this study provide insight into how t-Al₂O₃ promoted the interactions between the active components and silica support and how it can be used to aid in the selection of suitable wastewater treatment technologies.