High Ethanol Gas Sensitivity of Nano γ-Fe2O3/ZnO Double-Layer Films Prepared by the Screen Printing Technology and the Hydrothermal Method
The gas sensor with high ethanol gas sensitivity made of nano γ-Fe2O3/ZnO double-layer films was fabricated by the screen printing technology and the hydrothermal process with addition of citric acid (CA) surfactant based on Zn(NO3)2·6H2O and HMTA. XRD and SEM techniques were used to characterize the phases and morphologies of the films. The gas sensing properties of the gas sensor to ethanol were investigated. The result shows that the gas sensitivity of the nano γ-Fe2O3/ZnO double-layer films is higher than that of the nano γ-Fe2O3 single-layer film fabricated by the screen printing technology and the nano ZnO single-layer film fabricated by the hydrothermal process with addition of citric acid (CA) surfactant based on Zn(NO3)2·6H2O and HMTA, respectively. The high ethanol gas sensitivity of the nano γ-Fe2O3/ZnO double-layer films was caused by the nano effect and the special energy band structure