The modification effect of Fe2O3 nanoparticles on ZnO nanorods improves the adsorption and detection capabilities of TEA

Abstract

Surface modification is a simple and efficient method to enhance the gas sensing properties of semiconductor materials. In this paper, Fe₂O₃ nanoparticle-decorated ZnO nanorods are successfully fabricated by a facile two-step synthesis method. The SEM, TEM and XPS results indicate that the Fe₂O₃ nanoparticles grow directly on the surface of ZnO nanorods. The gas sensing properties of pure ZnO and Fe₂O₃/ZnO nanocomposites have been systematically analyzed. The gas response value of a 1 wt% Fe₂O₃/ZnO sample is 14.5 to 100 ppm triethylamine (TEA) at the optimal operating temperature of 260 °C, which is about 3 times that of pure ZnO (5.0). In addition, the 1 wt% Fe₂O₃/ZnO sensor reflects a rapid response/recovery time (1 s/14 s). The density functional theory (DFT) simulation results confirm that after the Fe₂O₃ cluster modifies the surface of ZnO, the atomic position at the interface changes significantly and the structure of Fe₂O₃/ZnO has the lowest adsorption energy for TEA molecules; these are the key factors for improving the gas sensitivity of the composite sample.