Enhanced Gas-Sensing Properties for Trimethylamine at Low Temperature Based on MoO₃/Bi₂Mo₃O₁₂ Hollow Microspheres

Most reported trimethylamine (TMA) sensors have to operate at high temperature, which will consume energy highly. To detect TMA at low temperature, it is necessary to modify the existing materials or develop new materials. In this paper, the sensor based on MoO3/Bi2Mo3O12 hollow microspheres can work at low operating temperature of 170 °C, which were prepared via a simple solvothermal route. The phase and morphology of the product were characterized by an X-ray diffraction meter, a scanning electron microscope and a transmission electron microscope. The surface chemistry of the MoO3/Bi2Mo3O12 sensor was studied with an X-ray photoelectron spectroscope to investigate the TMA sensing mechanism. The MoO3/Bi2Mo3O12 sensor (S = 25.8) had a higher response to 50 ppm TMA than those of MoO3 hollow spheres (S = 10.8) and Bi2Mo3O12 sensors (S = 4.8) at 170 °C. In contrast to the pure MoO3 and Bi2Mo3O12 sensors, the MoO3/Bi2Mo3O12 sensor exhibited an obviously enhanced gas-sensing property for TMA, which might be due to the heterostructure formed between MoO3 and Bi2Mo3O12 and the hollow morphology. It is the first time for MoO3/Bi2Mo3O12 to apply in gas sensors, which might take an important step in the application of MoO3/Bi2Mo3O12 or Bi2Mo3O12 in the field of gas sensing.