研制了一种基于多孔纳米氧化锡(SnO₂)催化剂的微催化燃烧式气体传感芯片(Pellistor). 基于微机电系统(Micro- Electro-Mechanical Systems, MEMS)工艺制备硅基封闭膜式微催化燃烧式传感器, 通过气相沉积技术在Pt微加热电极和高温绝缘层表面制备三维纳米氧化锡催化膜, 利用催化膜对氢气良好的催化特性, 采用惠斯通电桥电路进行测量, 实现对空气环境中氢气在0～4%浓度范围内的快速检测, 响应时间和恢复时间分别达到0.65 s和2.32 s, 灵敏度达75.4 mV/1% H₂, 线性度为99.4%. 考察200 天内该传感芯片对氢气的检测能力, 传感芯片表现出良好的稳定性, 精确度保持在95%以上. 在绝缘层高温性能稳定的条件下, 将三维纳米氧化锡应用于微催化燃烧式传感器的氢气检测, 对催化燃烧式传感器性能的改进具有重要的意义.

A new type of micro catalytic combustible gas sensor system was designed and fabricated using micro-electro mechanical system (MEMS) technology. A chemical vapor deposition (CVD) method is used to coat porous nano-crystalline SnO₂ catalyst layer. Tin chloride anhydrate vapor was used as the precursor, and it reacted with ammonium sulfide [(NH₄)₂S] to form tin disulfide (SnS₂) nanoparticles. The tin disulfide was dried up, annealed in air, then it transformed into polycrystalline SnO₂ nanoparticles. The X-ray diffraction (XRD) measurement was used to investigate the structural properties of the SnO₂ films. The morphology of the samples was investigated by field-emission scanning electron microscopy (FESEM). X-ray photoelectron spectroscopy (XPS) provided the information on chemical composition of the SnO₂ films. The sensing elements and the reference elements were connected to a Wheatstone bridge circuit for the measurement of gas-sensing properties. The catalytic combustion sensor exhibited relatively higher sensitivity (75.4 mV/1% H₂) and good linearity (99.4%) to H₂ from 0 to 4% V/V. The response and recovery times to 4% H₂ were 0.65 s and 2.32 s, respectively. Finally, the sensor signal was very stable during a 200 d long term operation (accuracy＞95%). It was noteworthy that the nano-structured SnO₂ as catalyst film in a catalytic combustible gas sensor could considerably improve the performance of the gas sensor. It can be used in realizing portable sensing devices such as hydrogen analyzers and hydrogen leak monitors.