Effect of the phase composition of iron oxide nanorods on SO2 gas sensing performance

alpha-FeOOH nanomds were synthesized by a facile precipitation method. gamma-Fe2O3 and alpha-Fe2O3 nanomds were then obtained by calcining for 6 h at 200 and 600 degrees C in ambient air, respectively. A mass-type sensor was developed based on the different iron oxide phase compositions of alpha-FeOOH, gamma-Fe2O3 and alpha-Fe2O3 coating a quartz crystal microbalance (QCM). The gas sensing properties of three as-prepared sensors were systematically examined for detecting sulphur dioxide gas (SO2) at room temperature. The effect of phase composition of iron oxide nanomds on sensing properties was also discussed. Although as-prepared iron oxides have a similar morphologic structure, the sensor based on gamma-Fe2O3 exposes the highest response to SO2. The sensing results show that the gamma-Fe2O3 coated QCM sensors had an extremely good performance for SO(2 )gas in the 2.5-20 ppm range at room temperature.

Automated summary

Alpha-FeOOH nanomaterials were synthesized and further calcined to obtain gamma-Fe2O3 and alpha-Fe2O3 nanomaterials. A mass-type sensor based on the different iron oxide phase compositions of these nanomaterials exhibited high sensitivity towards sulfur dioxide gas detection at room temperature. Among the sensors, gamma-Fe2O3 coated QCM sensors showed the best performance for SO2 gas detection in the range of 2.5-20 ppm at room temperature.