Background: We report for the first time that there is a considerable effect on the morphology
and optical properties of hematite (α-Fe2O3) nanoparticles by varying the precursor concentrations
from 1mmol to 3mmol. The nanoparticles were synthesized by combustion route using ferric nitrate,
citric acid and ammonia as precursors at an annealing temperature range of 600°C. Phase purity, morphological
studies and optical properties of the products were studied by powder X-ray diffraction
(XRD), Field emission scanning electron microscopy (FESEM), Raman spectroscopy and UV Visible
spectroscopy. The as-synthesized hematite nanoparticles have a mesoporous granular and somewhat
spherical structure with a bulk density ranging from 0.11 to 0.59gmcm-3.
Conclusion: The band gap of the as-synthesized α-Fe2
nanoparticles decreases from 1.96eV-1.77eV
with the decrease in the precursor concentration. Raman spectroscopy confirmed the formation of a
hematite phase of iron oxide nanoparticles. Practical percentage yield of the products increased from
47% to 65% with decrease in precursor concentrations.