Abstract

A two-step route to synthesize the hierarchical α-Fe₂O₃/ZnO hetero-nanostructures was demonstrated in this paper. In the first step, the nanosheet-assembled hierarchical flower-like ZnO nanosheets were synthesized, on which the α-Fe₂O₃ nanorods grew in the second step. The diameters of the most of the composite material are at the nanometer level. The thickness of the ZnO nanosheets is about 30 nm, and the diameter of the α-Fe₂O₃ nanorods is about 20 nm. For clearly know the gas sensing properties of α-Fe₂O₃/ZnO nanostructures, pure ZnO nanosheets and α-Fe₂O₃ nanorods were compared. The results demonstrated that the hierarchical α-Fe₂O₃/ZnO hetero-nanostructures-based sensor exhibited a higher response to trimethylamine than that of pure ones. The sensing performances of the hierarchical α-Fe₂O₃/ZnO hetero-nanostructures are significantly enhanced by the decoration of α-Fe₂O₃ nanorods on the surface of the ZnO nanosheets, which act as active groups to enhance catalytic activity and interfacial effect. This work has provided insights and strategies for the rational fabrication of high performance sensing material in the application of gas sensors.

Keywords

• α-Fe₂O₃/ZnO;  

• Hierarchical heterostructures;  

• Fast response time;  

• TMA gas sensor