Study on TiO2-SnO2 core-shell heterostructure nanofibers with different work function and its application in gas sensor

A core-shell heterostructure nanofibers (NFs) have been synthesized via a coaxial electrospinning approach. Two semiconducting metal oxides (SMOX) with different work function were selected to form the core-shell heterostructure NFs. In this work, SnO2 and TiO2 were chosen as the selected SMOXs for the synthesis of the core-shell heterostructure NFs. The electrons in TiO2 will flow to SnO2, because the work function of TiO2 is smaller than SnO2. This phenomenon could result in an increase of the electrons concentration in the SnO2 shell layers and the amount of adsorbed oxygen species increased. Therefore, the gas sensing properties of the TiO2-SnO2 core-shell heterostructure NFs were enhanced including a high response to the target gas, good selectivity to the target gas and the rapid response/recovery processes. The approach and results proposed in this study may contribute to the realization of more sensitive core-shell heterostructure NFs sensors.