基于ZnFe_2O_4纳米材料的低温型H_2S气敏元件的设计与实现

Design and Fabrication of H_2S Gas Sensor at Low Temperature Based on ZnFe_2O_4 Nanocrystalline

以无机盐为原料,液相合成了ZnFe2O4纳米粉体,通过XRD,TEM等手段对粉体的晶体结构、形貌等进行表征并研制了厚膜型气敏元件。结果表明:产物为尖晶石结构,粒径尺寸分布为10 nm^30 nm,平均粒径约为14 nm。在40℃~400℃的温度范围内,采用静态配气法测定元件的气敏性能,发现ZnFe2O4气敏元件在150℃的工作温度下对体积比浓度为1×10-3(V/V0)、1×10-4(V/V0)的H2S气体的灵敏度分别高达244.34和83.31;在此工作温度下对1×10-4(V/V0)的H2S气体响应时间2 s,恢复时间为5 s。在40℃对1×10-3(V/V0)的H2S气体的灵敏度达到111.00。

ZnFe2o4 nanocrystalline has been prepared from Zn（NO3）2·6H2O and Fe（NO3）3·9H2O by solution method for preparation of thick film gas sensor.The crystal structure and particle size of the samples are characterized by XRD and TEM. The results show that the powder of ZnFe2O4 is Spinel-type, and the mean grain size of the powder is about 14 nm in a range of 10 nm-30 nm. The gas sensing properties of the materials are tested in static slate at temperatures ranging from 40 to 400℃, revealing that the sensitivity of sensor to 1 ×10^-3（V/Vo） and 1 ×10^-4（V/Vo）H2S can reach 244.34 and 83.31 at working temperature of 150 ℃. At the optimum working temperature, its response and recovery time are 2 and 5 s. It has a high sensitivity of 111.00 when exposed to 1 ×10^-3（V/Vo） H2S at lower working temperature of 40 ℃.