Micro and Nano System Research Center, Key Lab of Advanced Transducers and Intelligent Control System, Ministry of Education & College of Information Engineering, Taiyuan University of Technology , Taiyuan, Shanxi 030024, China.
Anal Chem. 2018 Feb 6;90(3):1959-1966. doi: 10.1021/acs.analchem.7b04048. Epub 2018 Jan 11.
Selectivity is an important parameter of resistive-type gas sensors that use metal oxides. In this study, a highly selective toluene sensor is prepared using highly dispersed gold-nanoparticle-loaded zinc oxide nanoparticles (Au-ZnO NPs). Au-ZnO NPs are synthesized by coprecipitation and calcination at 400 °C with Au loadings of 0.15, 0.5, and 1.5 mol %. The Au NPs on ZnO are about 2-4 nm in size, and exist in a metallic state. Porous gas-sensing layers are fabricated by screen printing. The responses of the sensor to 200 ppm hydrogen, 200 ppm carbon monoxide, 100 ppm ethanol, 100 ppm acetaldehyde, 100 ppm acetone, and 100 ppm toluene are evaluated at 377 °C in a dry atmosphere. The sensor response of 0.15 mol % Au-ZnO NPs to toluene is about 92, whereas its sensor responses to other combustible gases are less than 7. Such selective toluene detection is probably caused by the utilization efficiency of the gas-sensing layer. Gas diffusivity into the sensing layer of Au-ZnO NPs is lowered by the catalytic oxidation of combustible gases during their diffusion through the layer. The present approach is an effective way to improve the selectivity of resistive-type gas sensors.
选择性是使用金属氧化物的电阻式气体传感器的一个重要参数。在这项研究中，使用高度分散的负载金纳米粒子的氧化锌纳米粒子（Au-ZnO NPs）制备了对甲苯具有高选择性的传感器。Au-ZnO NPs 通过共沉淀和在 400°C 下煅烧合成，Au 负载量为 0.15、0.5 和 1.5 mol%。ZnO 上的 Au NPs 约为 2-4nm 大小，并处于金属状态。通过丝网印刷制备多孔气体传感层。在 377°C 的干燥气氛下，评估了传感器对 200ppm 氢气、200ppm 一氧化碳、100ppm 乙醇、100ppm 乙醛、100ppm 丙酮和 100ppm 甲苯的响应。0.15mol%Au-ZnO NPs 对甲苯的传感器响应约为 92，而对其他可燃气体的传感器响应小于 7。这种对甲苯的选择性检测可能是由于气体传感层的利用效率。可燃气体在通过层扩散时的催化氧化降低了气体在 Au-ZnO NPs 传感层中的扩散能力。本方法是提高电阻式气体传感器选择性的有效途径。
