Robust cobalt perforated with multi-walled carbon nanotubes as an effective sensing material for acetone detection

Herein, we report the development of a facile hydrothermal method to fabricate plum and octahedron-like cobalt tetroxide (Co3O4) particles decorated with multi-walled carbon nanotube (MWCNT) one-dimensional (1D) hybrid structures. The morphology of Co3O4 particles on MWCNTs was controlled by changing the volume ratios of a mixed solvent of ethylene glycol and water. The Co3O4 particles grew on and across MWCNTs, resulting in structures with necklace-like morphology. The assembled MWCNTs/Co3O4 composites were used to detect acetone vapors and showed enhanced sensing performances than a pure MWCNT-based sensor. This enhanced gas sensing performance could be due to the structural integrity of the hybrid nanostructure as well as the surface defects and catalytic Co cations on the surfaces of MWCNT and Co3O4 octahedra, respectively.