气相法制备的WO3纳米粉体对CH4气敏性能的影响

Research of the CH4 Sensitivity of WO3 Nano Crystalline Powders Made from Gas-state Reaction

以传统的热分解法和新型的以纯钨丝为原料的气相反应法制备纳米WO3气敏材料，并以WO3为基材，制备了CH4气敏传感元件．气敏性能测试表明，热分解法制备的材料对CH4几乎没有气敏性能，而气相反应法制备出的WO3在2．5V加热电压下对5000ppm的CH4灵敏度均接近2．6．分析结果认为气相法制备的材料是非晶态的混合物，晶形呈菱形八面体状，晶粒间的缺陷是增加元件对CH4灵敏度的主要原因．

In this paper, WO3 nano crystalline powders are prepared by the traditional thermal decomposition method and gas-state reaction method, from which CH4 sensitive sensors are developed. Tests of gas sensitive performance indicate the products made from thermal decomposition have hardly no sensitivity to CH4, while the latter＇s sensitivity to 5000 ppm CH4 under 2.5 V of electricity amounts nearly to 2.6. The product made through the latter method is amorphous mixture in lozenge-shaped octagonal grains. The defect between grains is the major cause of the increase in the sensitivity to CH4 of sensors.