石墨烯为载体的Pd/SnO2合成及其CO气敏性能研究

Synthesis of Pd Doped SnO/Graphene Composites and Its Gas Sensing Properties to CO

采用沉淀法和超声浸渍法制备出不同石墨烯(G)载体量(Gx%)的二氧化锡(SnO2)复合材料,并成功负载贵金属钯(Pd)得到Pd1.5%/SnO2/Gx%复合材料。分析比较Pd1.5%/SnO2纳米复合材料及其石墨烯载体量分别为0.1%、0.25%、0.5%、0.75%(质量分数)的Pd1.5%/SnO2/Gx%复合材料对CO气敏性能。结果表明:石墨烯的加入在抑制SnO2纳米颗粒团聚的同时也提高了其均匀分散程度,从而提升Pd1.5%/SnO2/Gx%对CO的灵敏度。其中,Pd1.5%/SnO2/G0.25%对CO表现出更好的传感特性。在最佳工作温度75℃下,该复合材料对115 mg/m^3CO的灵敏度值为56.2,响应时间和恢复时间分别为7 s和10 s,且当CO质量浓度降至5.75 mg/m^3时,该传感器仍对CO具有较好响应。

SnO2 nanoparticles doped with different amounts of graphene were prepared by precipitation and ultrasonic impregnation methods.Pd1.5%/SnO2/Gx% composites were obtained by doping Pd using the impregnation method.The CO sensing properties of Pd1.5%/SnO2/Gx% nanocomposites doped with graphene at different ratio of 0.1%,0.25%,0.5% and 0.75%(mass fraction)were studied.The results showed that graphene could improve the sensitivity of Pd1.5%/SnO2/Gx% to CO by reducing the agglomeration and enhancing the dispersion of SnO2 nanoparticles.So Pd1.5%/SnO2/G0.25% had the excellent CO sensing properties.The optimum operating temperature was 75℃.When the CO concentration was 115 mg/m^3,the gas response could reach 56.2 and response,recovery time was 7 s and 10 s,respectively.The sample Pd1.5%/SnO2/G0.25% still had gas-sensing performance when the CO concentration was only 5.75 mg/m^3.