Investigation on the shape evolution of 1D mesoporous hematite nanoparticles prepared via anion-assisted hydrothermal approach

• 1D mesoporous hematite nanostructures are synthesized via anion assisted process.
• The structural evolution is investigated by considering the experimental conditions.
• Weak ferromagnetic behavior and high coercivity was observed in the samples.

The fabrication of one-dimensional (1D) porous hematite (α-Fe2O3) nanorods, nanotires and nanotubes employing an anion-assisted hydrothermal route is reported. The shape evolution of the resulting nanostructures is investigated taking into account the role of the phosphate and sulfate anions along with other experimental conditions. Field Emission Scanning Electron Microscope (FESEM) and High Resolution Transmission Electron microscope (HRTEM) images confirm the 1D morphology and porous nature of the prepared samples. Fourier Transform Infrared (FT-IR) and FT-Raman spectral analysis are carried out. Brunauer–Emmett–Teller (BET) measurements show the surface area and distribution of porosity in the as-prepared nanoparticles. The thermal stability of the samples is analyzed by employing Thermogravimetric (TG) and Differential Thermal Analysis (DTA). The effect of anisotropic shape over the magnetic property of the samples prepared under different synthetic conditions is studied using Vibrating Sample Magnetometer (VSM).

Hematite nanotires are formed by an anion assisted hydrothermal process at a temperature of 220 °C with a reaction time of 48 h. However, when the synthesis was carried out by including sulfate ion along with phosphate ion without altering the reaction temperature and time, it led to the formation of hematite NTs.Figure optionsDownload as PowerPoint slide