Preparation of Fe2O3/Fe foils by anodic oxidation in saturated NaF solution and calcination

Fe2O3/Fe foils were prepared by anodic oxidation of Fe foils in saturated NaF solution kept at 70°C and subsequent calcination at 400°C. The morphology of anodised Fe foils was affected remarkably by anodic voltage and time. When pulse anodisation was applied, clusters that consisted of nanograins were formed on the Fe foils. The X-ray diffraction and Fourier transform infrared data suggested that the cluster products transformed to Fe2O3 after calcining at 400°C for 2 h. According to thermogravimetry–differential scanning calorimetry data, the transformation began at ∼350°C. The Fe2O3/Fe anodes for Li ion batteries were analysed by means of cyclic voltammograms, electrochemical impedance spectroscopies and discharge/charge curves.