碳纳米管掺杂WO_3气敏元件敏感特性的研究

Study on sensing properties of WO_3 gas sensor doped with carbon nanotube

研究以碳纳米管（CNT）为掺杂剂制备的CNT-WO3旁热式气敏元件。采用球磨、超声分散的方法对碳纳米管进行分散处理，溶胶-凝胶方法制备WO3微粉，用SEM观察了WO3气敏材料的显微结构，测试了元件对丙酮的气敏性能。结果表明：碳纳米管存在于平均粒径为30-50nm的WO3晶粒间，从而增加了材料的气孔率。碳纳米管掺杂元件对丙酮的灵敏度远高于纯WO3元件，质量分数为0．4％的掺杂量对丙酮有最高灵敏度，具有能检测低体积分数丙酮气体、选择性好的优点，特别是掺杂碳纳米管明显提高了WO3元件的响应速度。

The tungsten oxide （WO3 ）gas sensor which is heater type are prepared by dopping with carbon nanotube（CNT）. Ball milling and ultrasonic dispersion are used to disperse CNT, SEM is used to identify the WO3 fine powders which prepared by sol-gel techniques, and the gas sensing properties of sensor is researched. The result shows carbon nanotubes exist in the WO3 grain which average particle size is about 30 - 50 nm, thus increasing the porosity of materials. CNT-WO3 gas sensor is more sensitive to acetone than pure WOasensor, and quality fraction 0.4 % is the optimal degree of adulteration for sensing to acetone, and it is good at low volume fraction, high selectivity ,fast response.