Nanostructured α-Fe۲O۳: Solvothermal Synthesis, Characterization, and Effect of Synthesis Parameters on Structural Properties

α-Fe۲O۳ is a stable, cheap, and non-toxic metal oxide with many advantages and different fields of application. Many attempts have been devoted to the synthesis of α-Fe۲O۳ with different crystal structures and morphologies to obtain the desired properties. In this research, nanostructured α-Fe۲O۳ were synthesized by a facile solvothermal route. The as-obtained samples are characterized by XRD, FESEM, EDS, FTIR, and BET surface area analysis. The results showed that the as-synthesized hematite consists of nanostructures with the morphology of distorted microspheres with an average diameter in the range of ۱ to ۱.۵ µm each composed of self-assembled nanoparticles with an average size in the range of ۱۰ to ۳۰ nm. The results showed that the hematite nanostructures had a specific surface area of ۴۱.۸۶ m۲g-۱. The influence of temperature and duration of the solvothermal process as well as, calcination on the structural properties of the α-Fe۲O۳ samples was investigated. The results reveal that the crystallite size of the samples increases with increasing the temperature and duration of solvothermal treatment. Moreover, calcination leads to an increase in the crystallite size of the samples. The α-Fe۲O۳ nanostructures with a minimum crystallite size of ۱۳.۶ nm were synthesized at ۱۵۰ °C for ۴ h while the largest crystallite size of ۷۵.۴ nm was obtained at ۱۸۰ °C and ۸ h with subsequent calcination of the sample at ۵۰۰ °C for ۱ h. The results of the present study can be useful to enhance the properties of α-Fe۲O۳ nanostructures in various fields of application.

Keywords:

Hematite (α-Fe۲O۳) , Nanostructures , Solvothermal process , Calcination , Crystallite Size