Concave Co3O4 octahedral mesocrystal: polymer-mediated synthesis and sensing properties

Abstract

Co₃O₄ mesocrystals with concave octahedral structures were successfully prepared by a facile, polymer-mediated route. The Co₃O₄ mesocrystals are obtained from the oriented aggregation of primary nanocrystals from their six identical [100] directions. After a thorough investigation of their structure as a function of the adopted preparation parameters such as reaction time and the amount of polymer, the gas sensing performance of the Co₃O₄ mesocrystals was studied with formaldehyde and ethanol as probe analytes. It was found that they show high sensitivity and good response and recovery characteristics. As compared with Co₃O₄ powder, the Co₃O₄ mesocrystals exhibit 1.8-fold and 1.4-fold enhancement in gas responses to 100 ppm of formaldehyde and ethanol, respectively.