Enhanced low-temperature gas-sensing performance of Fe2(MoO4)3 layered microplates

Iron molybdate [Fe₂(MoO₄)₃] particles with different morphologies were prepared by hydrothermal method using different reaction materials. The morphology, crystal phase, and microstructure were characterized by scanning electron microscopy and X-ray diffraction. The results indicate the Fe₂(MoO₄)₃ are micro-nano structure stacked by the nano-sheets. The Fe₂(MoO₄)₃ show spherical microspheres prepared by ferric nitrate and sodium molybdate, and layered microplates prepared by ferric chloride and ammonium molybdate. The sensors based on the Fe₂(MoO₄)₃ micro-nano structure exhibit good gas-sensing performances, especially to ethanol. Surprisingly, the response to ethanol is significantly higher than to other gases. Moreover, at the optimal operating temperature of 140 °C, the response of the sensors based on layered Fe₂(MoO₄)₃ is 63.8 for 100 ppm ethanol. In addition, the Fe₂(MoO₄)₃ sensors also show good repeatability and long-term stability. The results suggest that the layered Fe₂(MoO₄)₃ can be used as a potential highly sensitive and selective sensing material for ethanol detection at low temperature.