Methane Sensitivity of Alpha-Fe2O3 Obtained from Pechini Combustion Synthesis using Different Organic Fuels

Phase-pure alpha-iron-oxide (α-Fe2O3) nano-powders were obtained via Pechini gel-combustion using iron nitrates as an oxidant and different organic compounds (L-alanine, glycine, citric acid, oxalic acid, tartaric acid and urea) as fuels. The complex precursors isolated before the system's combustion were characterized by thermal analysis (TGA). After combustion, the as-synthesized powders were calcined at 600°C to obtain the α-Fe2O3 phase and eliminate the residual carbon. The powders prepared using different fuels were characterized using x-ray diffraction and field emission scanning electron microscopy. n-type gas sensitivity of thick film resistive sensors fabricated by using α-Fe2O3 powders was investigated in detail and it was observed that amongst the different fuels, citric acid-derived α-Fe2O3 is methane selective at 120°C operating temperature, examined in the presence of other similar types of resistive gas analyses of the same concentrations.