Fabrication of porous SnO₂ nanowires gas sensors with enhanced sensitivity

With large surface area, metal oxide porous nanostructures usually exhibited enhanced sensitivities when used as chemical sensors. In this work, porous SnO₂ nanowires (PNWs) with the diameter of about 130 nm and length up to 10 μm are synthesized by a controlled two-step method including electrospinning followed with hydrothermal etching treatment by Na₂S solution, which were used to fabricate high-performance gas sensors. Studies found that, compared with the electrospun pristine SnO₂ NWs without hydrothermal treatment, the SnO₂ PNWs exhibited remarkably enhanced gas sensing performances, including two times higher responsivity to ethanol. The method used here may be easily extended to synthesize other metal oxide nanostructures for high performance chemical sensors.