氧化镧掺杂对氧化锡粉体特性及气敏性的影响

Effects of La_2O_3 Doping on the Gas Sensitivity and Characteristics of SnO_2 Powders

利用高能球磨工艺,制备了不同氧化镧掺杂量的氧化锡粉体。研究了粉体的比表面积、微观形貌和物相结构,测试了镧掺杂前、后氧化锡粉体的本征电阻及其对乙醇的气敏性能。结果显示:随氧化镧掺杂量增加,氧化锡衍射峰沿2θ升高方向偏移,偏移程度先增大后恢复到原位置;对乙醇气体灵敏度先减小后增大。当氧化镧掺杂量为1.5%时,氧化锡衍射峰偏移最大,掺杂氧化锡粉体比表面积最大,掺杂氧化锡颗粒最小,电阻最低,对乙醇的灵敏度最低。说明氧化镧掺杂改善了氧化锡粉体对乙醇的气敏选择性。

Pure SnO2 and La203-doped SnO2 powders were prepared by high energy ball mill method. The phase composition and microstructure of the prepared powders were analyzed, and the specific surface area, resistance and gas sensitive property to ethanol vapor were tested. The results show that the shift of SnO2 diffraction peaks in the direction of higher increase first and then decrease back to the original location; while the gas sensitivity to ethanol vapor decreases first and then increases as the La2O3 increasing. When the content of La2O3 increases to 1.5% , the shift of SnO2 diffraction peak, the specific surface area of La2O3-doped SnO2 powder reach to the maximum value, and the particle size of powder, the electric resistance and the sensitivity to ethanol vapor change less. All these explain that the selectivity of SnO2 to ethanol gas can be improved by La2O3-doped.