Morphology adjustment of SnO2 and SnO2/CeO2 one dimensional nanostructures towards applications in gas sensing and CO oxidation

SnO2 and SnO2/CeO2 one dimensional (1D) nanostructures with various morphologies including solid nanofibers (NFs), nanobelts (NBs), nanotubes (NTs), and wire-in-tubes (WTs) were successfully prepared via a single-spinneret electrospinning process and a subsequent heat-treatment by adjusting the heating rate and the amount of CeO2. The interesting morphology evolution of samples from NTs to NBs was reported with increasing amounts of CeO2. In addition, SnO2 particles existed on the surface of the CeO2 matrix to form diverse structures in the 1D nanofibers. The band gap of the composite oxides decreased with the addition of CeO2. Compared with other nanostructures, SnO2/CeO2 NTs exhibited superior gas sensing properties, such as the highest response to ethanol. Due to the existence of Ce3+ and oxygen vacancies and the hollow structure, SnO2/CeO2 NTs revealed great CO oxidation performance, indicating the enhanced interactions between the catalyst and the target gas. These excellent properties were attributed to the prominent 1D hollow morphology, the good dispersion of SnO2 nanoparticles on the surface of the CeO2 matrix, the ideal crystallinity, and the composite interactions between the two oxides. In addition, the current method could be utilizable to fabricate other metal oxides with various morphologies for property controlling and important applications.