Green synthesis of ZnFe₂O₄@BC nanocrystals using pomelo peel waste for photo-Fenton degradation of dye under visible light

In this study, an economical ZnFe2O4@BC composite was successfully synthesized using pomelo peel biochar through a simple one-pot thermal-calcination roasting method. The combination of biochar and ZnFe2O4 was confirmed by FTIR, XRD, Raman, TEM, and XPS analysis, confirming that the successful insertion of carbon into the oxygen sites of the ZnFe2O4 lattice, forming C-O bonds. The incorporation of biochar resulted in a high specific surface area, providing more active sites for catalytic reactions, enhancing electron transport, effectively separating electron-hole pairs, increasing light capturing capacity, and restraining the leaching of metals. The Zn vacancy acted as an electron acceptor, promoting electron transfer in the catalyst by reducing the lowest unoccupied orbital position. Additionally, various reaction parameters such as solution pH, iron content, catalyst dosage, and H2O2 volume were investigated to elucidate their effects on the degradation performance. This study proposes a novel method for synthesizing carbon-coated metal oxide semiconductors, which shows great potential for environmental and energy-related applications.