Solvothermal synthesis of hierarchical Co3O4 flower-like microspheres for superior ethanol gas sensing properties

In this paper, hierarchical Co 3 O 4 flower-like microspheres have been successfully synthesized on the basis of morphology-conserved transformation method. The key step of this method is to construct flower-like microstructures of the cobalt-containing precursors via manipulating the synthetic parameters in a facile ethylene glycol mediated solvothermal reaction. The as-prepared flower-like microspheres are formed from the assembly of many two-dimensional nanosheets, accompanied by an outside-in dissolution and recrystallization process. Finally, hierarchical Co 3 O 4 microspheres with conserved flower-like morphology are obtained through the moderate calcination. When evaluated as a gas sensor, the obtained Co 3 O 4 flower-like microspheres exhibit a good response and sensitivity towards ethanol gas, suggesting their promising potential for gas sensors application.