Synthesis, Characterization and Photocatalytic Activity of α-Fe₂O₃/Bentonite Composite Prepared by Mechanical Milling

Preparation of α-Fe₂O₃/bentonite composite has been carried out by solid state reaction method by using iron ore from Aceh Besar district, Aceh as hematite source and bentonite from Kuala Dewa, North Aceh. The α-Fe₂O₃ was extracted from iron ore using hydrochloric acid and precipitated using ammonium hydroxide. The α-Fe₂O₃/bentonite composite was prepared by mixing α-Fe₂O₃ and bentonite at 4: 1 ratio using ball mill for 2 h. The XRD results showed that the dominant phase of iron ore was magnetite (Fe₂O₃) and was converted to α-Fe₂O₃ after extracting and calcined at 700 °C. The photocatalytic activity of α-Fe₂O₃/bentonit composite was evaluated on degradation of indigo carmine (IC) dye at various condition of pH, photocatalyst mass, initial dye concentration and irradiation time. The results showed that the highest photocatalytic activity of α-Fe₂O₃/bentonite composite was obtained at an initial pH of 1, a photocatalyst mass of 250 mg and an initial dye concentration of 5 mg/L with UV irradiation time for 2 h. The photocatalytic activity of α-Fe₂O₃/bentonite composite using solar light was higher than that of UV light.