1D N-type SnO2 nanofibers coexisted with P-type Co3O4 cubes for highly selective acetone sensor

1D n-type SnO2 nanofibers coexisted with p-type Co3O4 particles were synthesized by electrospinning with subsequent hydro-thermal process. The morphology and composition of Co3O4/SnO2 were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM). XRD patterns showed that the synthesized Co3O4/SnO2 were assigned to cubic Co3O4 and tetragonal rutile structure of SnO2 without any other impurity peaks. A possible growth mechanism was proposed to describe the formation of hierarchical SnO2 nanofibers coexisted with Co3O4 cubes. The Co3O4/SnO2 compound exhibited a relatively highly selective response to acetone and stable acetone sensing performance after a long period of aging. The Co3O4/SnO2 compound had a p-type response. It may be ascribed to the high coverage of ptype Co3O4 on n-type SnO2. The excellent acetone sensing properties of Co3O4/SnO2 nanostructures may be attributed to p-n junctions between Co3O4 and SnO2 nanograins as well as the unique coexistence structure of nanofibers and cubes.