We synthesized SnO2/NiO composite oxides by microwave-assisted liquid phase deposition to improve their surface physico-chemical properties and gas-sensing selectivity,and we investigated how the molar ratio of Ni^2+t...We synthesized SnO2/NiO composite oxides by microwave-assisted liquid phase deposition to improve their surface physico-chemical properties and gas-sensing selectivity,and we investigated how the molar ratio of Ni^2+to Sn^4+and the microwave power affected their gas-sensing performance.The microstructure,surface physico-chemical states,and morphology of the samples were characterized by X-ray diffraction,X-ray photoelectron spectroscopy,and scanning electron microscopy,respectively.Nitrogen adsorption-desorption isotherms were used to characterize the specific surface areas of the samples.Our results showed that microwave-assisted liquid phase deposition increased the surface-adsorbed oxygen content and the specific surface area of the SnO2/NiO composite oxide from about 22to 120m2/g.When the molar ratio of Ni^2+to Sn^4+was 0.1,the gas response to 1000ppm ethanol gas reached 84.7at a lower working voltage of 3.5V.However,the optimum working voltages for methanol and acetone gas were 4.5and 4.0V,respectively.Thus,a new method was found to improve the selectivity of the gas sensor.Moreover,at a working voltage of 4.0V,the gas response of a SnO2/NiO gas sensor synthesized by microwave-assisted liquid phase deposition with the optimum radiation power of 450W to 1000ppm acetone gas was 49.7,twice that of a sensor synthesized by traditional liquid phase deposition.展开更多
基金Shandong Province Natural Science Foundation of China (Grant No.ZR2015EL009).
文摘We synthesized SnO2/NiO composite oxides by microwave-assisted liquid phase deposition to improve their surface physico-chemical properties and gas-sensing selectivity,and we investigated how the molar ratio of Ni^2+to Sn^4+and the microwave power affected their gas-sensing performance.The microstructure,surface physico-chemical states,and morphology of the samples were characterized by X-ray diffraction,X-ray photoelectron spectroscopy,and scanning electron microscopy,respectively.Nitrogen adsorption-desorption isotherms were used to characterize the specific surface areas of the samples.Our results showed that microwave-assisted liquid phase deposition increased the surface-adsorbed oxygen content and the specific surface area of the SnO2/NiO composite oxide from about 22to 120m2/g.When the molar ratio of Ni^2+to Sn^4+was 0.1,the gas response to 1000ppm ethanol gas reached 84.7at a lower working voltage of 3.5V.However,the optimum working voltages for methanol and acetone gas were 4.5and 4.0V,respectively.Thus,a new method was found to improve the selectivity of the gas sensor.Moreover,at a working voltage of 4.0V,the gas response of a SnO2/NiO gas sensor synthesized by microwave-assisted liquid phase deposition with the optimum radiation power of 450W to 1000ppm acetone gas was 49.7,twice that of a sensor synthesized by traditional liquid phase deposition.
