In order to develop a sensor for the detection of toxic N2O molecules, the interaction of pristine and Aldoped BN nanosheets with an N2O molecule was investigated using density functional theory calculations. It was f...In order to develop a sensor for the detection of toxic N2O molecules, the interaction of pristine and Aldoped BN nanosheets with an N2O molecule was investigated using density functional theory calculations. It was found that unlike the pristine sheet, the Al-doped sheet can effectively interact with the N2O molecule so that its electronic properties and conductivity are dramatically changed. We believe that replacing a B atom of the BN sheet with an Al atom may be a good strategy for improving the sensitivity of these nanosheets toward N2O, which cannot be trapped and detected by the pristine sheet.展开更多
In this study, the Yb（1-x）CaxFeO3（0≤x≤0.3） nanocrystalline powders were prepared by sol-gel method. We used the method of quantitative analysis to research the gas-sensitive properties for Yb（1-x）CaxFeO3 to CO...In this study, the Yb（1-x）CaxFeO3（0≤x≤0.3） nanocrystalline powders were prepared by sol-gel method. We used the method of quantitative analysis to research the gas-sensitive properties for Yb（1-x）CaxFeO3 to CO2. Also, we investigated the effects of various factors on gas sensing properties by simple variable method. The doping of Ca could not only decrease the resistance of YbFeO3, but also enhance its sensitivity to CO2. When the Ca content x=0.2, Yb（1-x）CaxFeO3 showed the best response to CO2. The response Rg/Ra to 5000 ppm CO2 for Yb（0.8）Ca（0.2）FeO3 at its optimal temperature of 260 °C with the room temperature humidity of 28%RH was 1.85. The response and recovery time decreased with an increase of the operating temperature for Yb（0.8）Ca（0.2）FeO3 sensor to 5000 ppm CO2. Furthermore, with an increase of CO2 concentration from 1000 to 50000 ppm, the response time of Yb（0.8）Ca（0.2）FeO3 became shorter, and meanwhile the recovery time was longer. CO2-sensing response for Yb（0.8）Ca（0.2）FeO3 increased with the increase of relative humidity. The response for Yb（0.8）Ca（0.2）FeO3 in the background of air（with the room temperature humidity of 39%RH） at 260 °C could reach 2.012 to 5000 ppm CO2, which was larger than the corresponding value（1.16） in dry air.展开更多
文摘In order to develop a sensor for the detection of toxic N2O molecules, the interaction of pristine and Aldoped BN nanosheets with an N2O molecule was investigated using density functional theory calculations. It was found that unlike the pristine sheet, the Al-doped sheet can effectively interact with the N2O molecule so that its electronic properties and conductivity are dramatically changed. We believe that replacing a B atom of the BN sheet with an Al atom may be a good strategy for improving the sensitivity of these nanosheets toward N2O, which cannot be trapped and detected by the pristine sheet.
基金Project supported by the National Natural Science Foundation of China(51272133,51472145,51472150)
文摘In this study, the Yb（1-x）CaxFeO3（0≤x≤0.3） nanocrystalline powders were prepared by sol-gel method. We used the method of quantitative analysis to research the gas-sensitive properties for Yb（1-x）CaxFeO3 to CO2. Also, we investigated the effects of various factors on gas sensing properties by simple variable method. The doping of Ca could not only decrease the resistance of YbFeO3, but also enhance its sensitivity to CO2. When the Ca content x=0.2, Yb（1-x）CaxFeO3 showed the best response to CO2. The response Rg/Ra to 5000 ppm CO2 for Yb（0.8）Ca（0.2）FeO3 at its optimal temperature of 260 °C with the room temperature humidity of 28%RH was 1.85. The response and recovery time decreased with an increase of the operating temperature for Yb（0.8）Ca（0.2）FeO3 sensor to 5000 ppm CO2. Furthermore, with an increase of CO2 concentration from 1000 to 50000 ppm, the response time of Yb（0.8）Ca（0.2）FeO3 became shorter, and meanwhile the recovery time was longer. CO2-sensing response for Yb（0.8）Ca（0.2）FeO3 increased with the increase of relative humidity. The response for Yb（0.8）Ca（0.2）FeO3 in the background of air（with the room temperature humidity of 39%RH） at 260 °C could reach 2.012 to 5000 ppm CO2, which was larger than the corresponding value（1.16） in dry air.
