Ionic Liquid Assisted Synthesis of α-Fe2O3 Nanospheres Based on Potassium Acetate Solution and Their Gas-sensing Properties

alpha-Fe2O3 nanospheres with good crystallinity and uniformity, diameter of 10-30 nm were synthesized from FeCl3 center dot 6H(2)O and CH3 COOK with 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) as ionic liquid structure-based agent and surfactant by hydrothermal method at a constant temperature of 150 degrees C for 8 h. The effects of different amounts of [Bmim]Cl on the formation of iron oxide and its gas sensing properties were investigated. The gas-sensing results show that alpha-Fe2O3 nanospheres exhibit the best gas-sensing properties to ethanol when the amount of ionic liquid is 12 mmol. When the working temperature is 300 degrees C , the sensitivity of as-prepared alpha-Fe2O3 nanospheres to 50 mu L/L ethanol is 7.56, which is 5.6 times that of alpha-Fe2O3 generated without ionic liquid. There is also a good linear relationship (R = 98.8%) in the range of 10-200 mu L/L, and the sensor has good selectivity and stability. In addition, the gas-sensing mechanism of alpha-Fe2O3 nanospheres to ethanol, and the influence of operating temperature on its gas-sensing properties were discussed in detail.