瓶状InN-In2O3纳米复合材料的制备及增强的甲醛气敏性能

采用溶胶-凝胶法制备了In₂O₃纳米粉体, 通入NH₃进行反应得到了中间产物InN基底材料, 再通过原位氧化过程最终获得了InN-In₂O₃纳米复合材料, 并利用X射线衍射仪(XRD)、 扫描电子显微镜(SEM)、 透射电子显微镜(TEM)、 X射线光电子能谱仪(XPS)等对所制备材料的组成、 形貌及结构等进行了表征测试. 结果表明, 该纳米复合材料呈瓶状结构. 气敏性能测试结果表明, 其在较低工作温度(75 ℃)下对甲醛气体的检出限可低至ppb级(1 ppb=1.3 μg/m³), 具有灵敏度较高(对0.13 mg/m³即100 ppb甲醛的灵敏度为12)、 响应时间较短(2 s)以及选择性和稳定性较强的优良性能. 在湿度对传感器灵敏度的影响测试中, 由于甲醛的水溶特性, 随着湿度的变化, 传感器的灵敏度发生变化. 在低甲醛浓度时湿度的变化对灵敏度的影响较大, 高浓度时影响反而较小.

Preparation of InN-In2O3 Nanocomposite with Bottle-shaped Structure and Its Enhanced Formaldehyde Gas Sensitivity

The In₂O₃ nano-powder was prepared by sol-gel method， and by reacting with NH₃， the interme- diate product InN base material was obtained， then the InN-In₂O₃ nanocomposite was obtained through the in?situ oxidation process， and characterized by means of XRD（X-ray differaction）， SEM（scanning electron microscopy）， TEM（transmission electron microscopy） and XPS（X-ray photoelectron spectroscopy）. The bottle-shaped nanocomposite was then equipped with a micro-chip sensor chip working platform. The results show that at a lower operating temperature（75 ℃）， the detection limit for formaldehyde gas can be as low as ppb（0.13 mg/m³ or 100 ppb）， with higher sensitivity（12）， shorter response time（2 s）， selectivity and stability. In the test of the influence of humidity on the sensitivity of the sensor， due to the water-soluble characteristics of formaldehyde， the sensitivity of the sensor changes with the change of humidity. This change is great when the concentration of formaldehyde is low， but small when the concentration of formaldehyde is high.