La_2O_3掺杂WO_3纳米粉体的制备及气敏性能

以胶溶法制备的WO3和sol-gel法制备的La2O3为原料,采用固相研磨法制备了掺杂剂质量分数w(La2O3)为0.5%～7.0%的La2O3-WO3纳米粉体,利用XRD、TEM等测试手段分析了粉体的微观结构,采用静态配气法测试了由所制粉体制成的气敏元件对丙酮的气敏性能。结果表明,制得的La2O3-WO3纳米粉体结晶良好,平均粒径为60nm;当工作电压为4.5V,w(La2O3)为5.0%时,粉体在600℃下烧结制得的气敏元件对体积分数为50×10–6的丙酮的灵敏度可达37.6,响应时间和恢复时间分别是1s和11s。

Preparation and gas sensing property studies of La2O3-doped WO3 nanopowder

La2O3-doped WO3 nanopowder containing 0.5%～7.0%(mass fraction) of La2O3 was prepared from La2O3 and WO3 by the solid state grinding method.The WO3 and La2O3 used were prepared by the colloidal chemistry method and sol-gel method,respectively.The microstructure of the prepared powder was characterized with XRD and TEM,while the sensitivity of the gas sensor fabricated from the prepared nanopowder to acetone was evaluated via the static volumetric method.The results indicate that the La2O3-doped WO3 nanopowder shows a high degree of crystallization and an average size of 60 nm.For the gas sensors fabricated from the nanopowder containing 5.0%(mass fraction) of La2O3 under a sintering temperature of 600℃,their sensitivity to acetone(volume fraction:50×10–6) reaches 37.6 at a working voltage of 4.5 V,and they exhibit superior response-recovery characteristics with a response time of 1s and a recovery time of 11 s.