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

Abstract

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.