Electrospun nanofibers of CuOSnO2 nanocomposite as semiconductor gas sensors for H2S detection

We report the synthesis of CuOSnO2 nanocomposite nanofibers of various chemical compositions via electrospinning as well as their excellent H2S sensing capabilities. The results of X-ray diffraction and high-resolution electron transmission microscopy demonstrate that the nanofibers are a mixture of the tetragonal rutile structure of SnO2 and the monoclinic structure of CuO in the form of nanograins. Each nanograin shows a single phase of either CuO or SnO2, instead of forming their solid-solution phase. In other words, a CuOSnO2 nanocomposite structure is realized in a true sense. The sensing properties of the CuOSnO2 nanocomposite nanofibers are well explained based on the creation and extinction of the p-n junctions between CuO and SnO2 nanograins. The p-n junctions that are readily created in such nanocomposite due to the presence of nanograins as well as the high specific surface area provided by the one-dimensional nanofiber shape are responsible for the outstanding H2S sensing performances of the CuOSnO2 nanofibers.