Hierarchical structure with heterogeneous phase as high performance sensing materials for trimethylamine gas detecting

A two-step route to synthesize the hierarchical alpha-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 alpha-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 alpha-Fe2O3 nanorods is about 20 nm. For clearly know the gas sensing properties of alpha-Fe2O3/ZnO nanostructures, pure ZnO nanosheets and alpha-Fe2O3 nanorods were compared. The results demonstrated that the hierarchical alpha-Fe2O3/ZnO hetero-nanostructures-based sensor exhibited a higher response to trimethylamine than that of pure ones. The sensing performances of the hierarchical alpha-Fe2O3/ZnO hetero-nanostructures are significantly enhanced by the decoration of alpha-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. (C) 2015 Elsevier B.V. All rights reserved.