Synthesis of ZnO@Fe2O3 microflowers with enhanced performance in volatile organic compound detection

Abstract

Metal-oxide semiconductor is widely applied in gas sensor for volatile organic compound detection. However, these sensors usually exhibit poor selectivity and inferior sensitivity. Here, ZnO@Fe2O3 microflowers were synthesized using FeOOH microflowers as precursors via a simple solution reaction route, followed by heat treatment. The ZnO@Fe2O3 microflowers were characterized using a series of techniques, and their sensing responses to volatile organic compounds (VOCs) were evaluated in comparison with those of pristine Fe2O3. The ZnO@Fe2O3 microflower sensor exhibited better responses to several gases, especially acetone, with a response of 74.3 towards 100 ppm acetone, which is 2.85 times higher than that of the Fe2O3 microflower sensor. The sensor also presented high selectivity, reproducibility, and stability in sensing different VOCs. The large specific surface area, heterostructure, favorable hierarchical flower-like nanostructure assembled by the nanosheets, and high porosity of the ZnO@Fe2O3 microflowers contributed to its enhanced gas-sensing responses. Overall, this synthetic strategy for fabricating flower-like ZnO@Fe2O3 nanostructures can be widely applied.