Ball milling synthesis of ZnO/α-Fe₂O₃ nanocomposite as a photocatalyst for degradation of indigo carmine dye Available to Purchase

ZnO/α-Fe₂O₃ nanocomposite have been synthesized by a ball milling technique and applied for indigo carmine dye degradation in aqueous solutions. ZnO and α-Fe₂O₃ with the mole ratio of 1 : 5 were mixed without solvent in a planetary mill at the milling speed of 350 rpm for 2 h. X-ray Diffraction (XRD) and Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDS) were used to characterize individual and nanocomposite samples. Based on XRD results it is known that the average crystallite size of α-Fe₂O₃, ZnO, and ZnO/α-Fe₂O₃ nanocomposite determined by using Scherer’s formula are 52.40 nm, 39.47 nm, and 47.07 nm. SEM images show that α-Fe₂O₃ particles are highly homogeneous in shape and size, while the image of ZnO/α-Fe₂O₃ nanocomposite confirmed the presence of ZnO in α-Fe₂O₃ surface. Compare to α-Fe₂O₃ and ZnO, ZnO/α-Fe₂O₃ nanocomposite showed higher photocatalytic activitiy for degradation of indigo carmine under UV irradiation. Some parameter conditions such as the pH of indigo carmine solution, ZnO/α-Fe₂O₃ nanocomposite dosage, and indigo carmine concentration also studied in detail. The highest degradation percentage of indigo carmine was obtained by using 250 mg of ZnO/α-Fe₂O₃ nanocomposite, the initial pH of indigo carmine solution is 1, and indigo carmine concentration is 15 mg/L at the irradiation time under UV light for 120 minutes and 90 minutes under solar light.