Detection of triethylamine with fast response by Al2O3/α-Fe2O3 composite nanofibers

Pure α-Fe2O3 nanotubes and a series of Al2O3/α-Fe2O3 composite nanofibers were synthesized via facile electrospinning and subsequent calcination at 500 °C in air for 2 h. The morphologies and nanostructures of these samples were characterized through various experimental techniques. It was found that the composite samples were composed of crystal α-Fe2O3 and amorphous Al2O3. The composite Al2O3/α-Fe2O3 nanofibers have smaller grain size than that of pure α-Fe2O3 nanotubes prepared by the same process. Furthermore, comparative gas sensing investigation between Al2O3/α-Fe2O3 composite nanofibers and pure α-Fe2O3 nanotubes was performed to show the superior sensing properties of the composite samples. When the mass ratio of Al source and Fe source was 1:4, the sensor exhibited the highest response to 100 ppm triethylamine at 250 °C. It is worth noting that the response times were no more than 2 s at operating temperatures ranged from 175 °C to 300 °C. Finally, the related mechanism of gas sensing and the role of Al2O3 in the composite nanofibers were discussed in this paper.