Cr2O3掺杂TiO2纳米粉体的制备及气敏性能研究

Preparation and gas sensing property studies of Cr_2O_3-doped TiO_2 nanopowder

以钛酸四丁酯、硝酸铬为原料,采用sol-gel法制备了w（Cr2O3）为0~30%的Cr2O3-TiO2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乙醇、CO、NO2等气体的气敏性能。结果表明：用该法得到的粉体材料颗粒粒径小,且均匀;工作电压为4.0 V时,由w（Cr2O3）为20%的粉体在800℃烧结制得的气敏元件对体积分数为30×10–6的乙醇的灵敏度最高可达282,且具有较好的响应–恢复特性,响应时间和恢复时间分别是10 s和24 s。

Cr2O3-doped TiO2 nanopowders containing 0~30% Cr2O3 were prepared from Ti（OC4H9）4 and Cr（NO）3·9H2O by the sol-gel method,and their microstructure was characterized by XRD and TEM.Gas sensors were fabricated from the prepared nanopowders,and the sensitivity of them to alcohol、CO、NO2 were measured via the static volumetric method.The results indicate that the particle size of obtained nanopowders is small and constant.For sensors fabricated from nanopowders containing 20% Cr2O3 under a sintering temperature of 800 ℃,the maximum sensitivity to ethanol（volume fraction： 30×10–6） reaches 282 at a working voltage of 4 V;Moreover,such sensors exhibit superior response-recovery characteristics,and their response time and recovery time are 10 s and 24 s,respectively.