Synthesis and Gas Adsorption Properties of γ ‐Fe2O3 Nanoparticles for Mass‐Type Sensing Application

Abstract In this study, Fe 3 O 4 nanoparticles are prepared by the co‐precipitation method. γ‐Fe 2 O 3 and α‐Fe 2 O 3 nanoparticles are obtained by calcining Fe 3 O 4 nanoparticles for 6 h at 200 and 600 °C. The physicochemical properties of the prepared nanoparticles are investigated by field‐emission scanning electron microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, and Barrett–Joyner–Halenda methods. The gas sensors based on a quartz crystal microbalance (QCM) coated with Fe 3 O 4 , γ‐Fe 2 O 3 , and α‐Fe 2 O 3 nanoparticles are fabricated and analyzed. The as‐fabricated QCM sensors displayed a high capability for detecting SO 2 at room temperature. Among the sensors, the γ‐Fe 2 O 3 nanoparticles coated QCM sensor exhibited the best response. Moreover, the sensor shows good repeatability and long‐term stability. The correlation between the phase composition of the iron oxide nanoparticles and SO 2 sensing performance is also discussed in detail.