Room-temperature solid state synthesis of ZnO/α-Fe2O3 hierarchical nanostructures and their enhanced gas-sensing properties

A facile solid state reaction route was employed to synthesize the ZnO/α-Fe2O3 hierarchical nanostructures by grinding zinc acetate, α-Fe2O3 and sodium hydroxide with proper molar ratios together at room temperatures without any surfactant and template. Their morphological feature was characterized as self-assembled by nanosheets on which α-Fe2O3 nanoparticles were well sprinkled, and it was observed that the amount of α-Fe2O3 added significantly affected the overall morphology. Furthermore, gas-sensing properties of the obtained products were studied. The results demonstrated that the sensors based on ZnO/α-Fe2O3 hierarchical nanostructures exhibited a much higher sensitivity to ethanol vapor than the sensors based on pure ZnO nanostructures and the 2% α-Fe2O3-added ZnO/α-Fe2O3 nanostructures sensors showed the highest sensitivity. Additionally, the mechanism of gas sensing was also studied.