Gas sensing properties of SnO2 hollow spheres/polythiophene inorganic–organic hybrids

SnO2 hollow spheres/polythiophene hybrid materials were synthesized by an in situ chemical oxidative polymerization method, and characterized by Fourier transfer infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM) and thermo-gravimetric analysis (TGA). It is proved that there is a strong synergetic interaction between the SnO2 hollow spheres and polythiophene, and the hybrid materials had higher thermal stability than pure polythiophene, which is beneficial for potential application as chemical sensors. Gas sensing tests showed that the gas sensor based on the as-obtained hybrids had high sensor response and good selectivity, as well as comparatively short recovery time to NO2 at a working temperature of 90 °C. The enhanced gas sensing performance of the hybrids is due to the high surface area of the hybrids and the p–n heterojunction formed between p-type polythiophene and n-type SnO2 hollow spheres.