Removal of Phenolic Compounds from Water Using Copper Ferrite Nanosphere Composites as Fenton Catalysts

• Published in: Nanomaterials (Basel, Switzerland) Vol. 9; no. 6; p. 901
• Main Authors: Moreno-Castilla, Carlos, López-Ramón, María Victoria, Fontecha-Cámara, María Ángeles, Álvarez, Miguel A, Mateus, Lucía
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 20-06-2019; MDPI
• Subjects: Aminophenol; Aqueous solutions; Catalysts; Catalytic activity; Catalytic oxidation; Copper; Copper compounds; Copper ferrite; cuprite; Degradation; Electron microscopy; Fenton reaction; Fourier transforms; Infrared spectroscopy; Ions; Magnetic measurement; Mineralization; Morphology; Nanospheres; Nitrophenol; Organic carbon; p-Aminophenol; p-Nitrophenol; Phase transitions; Phenolic compounds; Phenols; Photoelectron spectroscopy; Photoelectrons; Pollutants; Polymer matrix composites; Roasting; Scanning electron microscopy; synergic effects; Total organic carbon; Transmission electron microscopy; X ray photoelectron spectroscopy; X-ray diffraction; United States > US; Germany; Spain; copper ferrite; synergic effects; phenols; Fenton reaction; cuprite
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano9060901

Copper ferrites containing Cu
ions can be highly active heterogeneous Fenton catalysts due to synergic effects between Fe and Cu ions. Therefore, a method of copper ferrite nanosphere (CFNS) synthesis was selected that also permits the formation of cuprite, obtaining a CFNS composite that was subsequently calcined up to 400 °C. Composites were tested as Fenton catalysts in the mineralization of phenol (PHE),
-nitrophenol (PNP) and
-aminophenol (PAP). Catalysts were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and magnetic measurements. Degradation of all phenols was practically complete at 95% total organic carbon (TOC) removal. Catalytic activity increased in the order PHE < PNP < PAP and decreased when the calcination temperature was raised; this order depended on the electronic effects of the substituents of phenols. The as-prepared CFNS showed the highest catalytic activity due to the presence of cubic copper ferrite and cuprite. The Cu
surface concentration decreased after calcination at 200 °C, diminishing the catalytic activity. Cuprite alone showed a lower activity than the CFNS composite and the homogeneous Fenton reaction had almost no influence on its overall activity. CFNS activity decreased with its reutilization due to the disappearance of the cuprite phase. Degradation pathways are proposed for the phenols.