Synthesis of pristine In2O3/ZnO–In2O3 composited nanotubes and investigate the enhancement of their acetone sensing properties

Pristine In 2 O 3 and ZnO–In 2 O 3 composited nanotubes were synthesized by the electrospinning technic and followed by calcination . The formation of ZnO–In 2 O 3 n–n heterojunctions was found to be highly sensitive to acetone gas. X-ray powder diffraction (XRD), Scanning electron microscope (SEM) and energy dispersive X-ray spectrometry (EDS) were respectively used to characterize surface crystallinity and morphology. The possible mechanism of nanotubes formation was also investigated. Gas sensors were made based on the as-synthesized materials to investigate their gas sensing properties. Compare with the pristine In 2 O 3 nanotubes, ZnO–In 2 O 3 composite nanotubes show the obviously improved of acetone sensitivity. The sensitivity of ZnO–In 2 O 3 composite nanotubes is about 43.2, which is about triple times larger than that of the pristine In 2 O 3 nanotubes to 60   ppm acetone at 280   °C. The response and recovery times of ZnO–In 2 O 3 nanotubes to 60   ppm acetone are about 5 and 25   s. In addition, ZnO–In 2 O 3 composite nanotubes sensor also possesses a good selectivity to acetone.