Gas response properties of citrate gel synthesized nanocrystalline MgFe2O4: Effect of sintering temperature

Graphical abstract: Display Omitted Highlights: ► Synthesis of nanocrystalline MgFe2O4 by economical citrate gel combustion method. ► Structural, morphological, and gas response properties of MgFe2O4. ► Enhancement in selectivity of MgFe2O4 towards LPG with sintering temperature. ► Use of MgFe2O4 to detect different gases at different operating temperatures. -- Abstract: Spinel type MgFe2O4 material was synthesized by citrate gel combustion method. The effect of sintering temperature on structural, morphological, and gas response properties was studied. The powder X-ray diffraction pattern and transmission electron microscope study confirms nanocrystalline spinel structure of the synthesized powder. The material was tested for response properties to various reducing gases like liquid petroleum gas (LPG), acetone, ethanol, and ammonia. The results demonstrated n-type semiconducting behavior of MgFe2O4 material. It was revealed that MgFe2O4 sintered at 973 K was most sensitive to LPG at 648 K and to acetone at 498 K. However MgFe2O4 sintered at 1173 K exhibited higher response and selectivity to LPG with marginal increase in the operating temperature. Furthermore, the sensor exhibited a fast response and a good recovery. It was observed that the particles size, porosity, and surface activity of the sensor material is affected by the sintering temperature.