Effect of Copper Nitrate on the Preparation of α-Fe₂O₃ Powder and its Photo-catalytic Performance

The α-Fe₂O₃ nano-composites with photo-catalytic activity were prepared by solution combustion synthesis using ferric nitrate,copper nitrate and glycine as raw materials.The grain size of α-Fe₂O₃ is about 30 nm.The products were characterized by XRD,SEM and TEM.The effects of copper nitrate content on phase morphology and photo-catalytic properties of α-Fe₂O₃ composites were studied.The addition of cupric nitrate affects the energy released during the reaction and the morphology changes from flocculent flaky to sheet.When the copper nitrate amount is 1g,the photo-catalytic performance of α-Fe₂O₃ composites material is optimal,and the MB solution with the initial concentration of 20×10^-6 is degraded within 50 min.This is due to the narrow band gap width of CuFe₂O₄,which can absorb more sunlight.Meanwhile,it can form heterojunction with α-Fe₂O₃,improve the transmission of photo-generated electrons and holes,reduce the recombination of photo-generated electrons and holes,and thus improve the catalytic activity of powder.