| NASICON type(Al0.2Zr0.8)4/3.8Nb?PO4?3 has important application research on electrochemical sensors.At present,the addition of sintering aids and ion doping are the most common method for improving the sintering properties and the electrical conductivity.The Hf-doped solid electrolyte(Al0.2Zr0.8)4+x/3.8Nb1-xHfx?PO4?3?x=0?0.2?was prepared by high temperature solid phase method.The conductivity of the sample(Al0.2Zr0.8)4.1/3.8Nb0.9Hf0.1?PO4?3?x=0.1?is the highest,and the conductivity at 500 °C was 2.77×10-4 S·cm-1,which is 1.26 times undoped at the same temperature.The number of ion migrations is above 0.99,indicating that the electrolyte is only Al3+ ion-conducting.The Sb-doped solid electrolyte(Al0.2Zr0.8)4/3.8Nb1-xSbx?PO4?3?x=0?0.15?was prepared by high temperature solid phase method.The conductivity of the sample(Al0.2Zr0.8)4/3.8Nb0.95Sb0.05?PO4?3?x=0.05?is the highest,and the conductivity at 500 °C is 3.81×10-4 S·cm-1,which is 1.73 times undoped at the same temperature.The number of ion migrations is above 0.99,indicating that the electrolyte is only Al3+ ion-conducting.The(Al0.2Zr0.8)4/3.8Nb?PO4?3 with LiF was fabricated by high temperature solid reaction method.When the addition amount of sintering aid LiF is 4 wt%,the electrolyte has the highest density and conductivity,and its conductivity reaches 2.45×10-3 S·cm-1 at 500 °C,which is 11.1 times as high as that of sample without sintering additives.The ionic transfer numbers of the electrolyte measured by DC polarization method are above 0.999,indicating that the solid electrolyte is mainly Al3+ ion conduction.On the basis of(Al0.2Zr0.8)4/3.8Nb?PO4?3 with 4% LiF electrolyte and CrVO4 sensing material,a mixed potential type of NH3 sensor was prepared and tested.The NH3 gas sensor displays excellent sensing performance with a sensitivity of 90.2 m V/decade at 300 °C.The Al sensor based on(Al0.2Zr0.8)4/3.8Nb?PO4?3 responds quickly,and the Nernst equation is satisfied between the response value and the aluminum concentration.Figure 35;Table 9;Reference 65... |
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