丙酮气体传感器的PANI/Au/Al_2O_3电极制备工艺优化

Process optimization for preparing acetone gas sensor based on PANI / Au / Al_2O_3 electrode

以微制程技术及电化学法制备PANI／Au／Al2O3电极，并组装成电阻式丙酮气体传感器。以恒电流法在不同电流密度下进行三阶段聚合，并利用混合物实验设计法对纳米结构PANI／Au／Al2O3电极的最佳制备工艺条件进行了优化。结果表明：分别固定聚合电流密度为40，60，80p．A／cm2进行三阶段聚合，当聚合电流密度按由小到大顺序，所得的PANI／Au／Al2O3电极稳定性最好。固定聚合电量为35mC，当三阶段电量比为0．35：0．33：0．32时，对于9958×10-6丙酮得到最大的感测电阻变化率为7．55％。丙酮气体浓度在（475—1189）×10-6与（23～118）×10-6范围内，对应灵敏度分别为1．2×10-3和6．4×10-3％／10-6，平均响应时间为3min。

In order to obtain a better performance of resistive acetone gas sensor, based on micro process technology and electrochemical methods, PANI/Au/Al2O3 electrode is prepared and assembled. Three-phase polymerization is carried out with different current density. Use mixture experimental design method, preparation process of nanostructure of PANI/Au/Al2O3 electrode is optimized. Results show that the stability of PANI/Au/ Al2O3 electrode is the best when polymerization current density is fixed at 40,60 and 80μA/cm2, respectively, and the aggregate current density change from small to large. Maintaining polymerization charge at 35 mC, as three- phase charge ratio is 0.35 ： 0. 33 ： 0.32, the maximum sensor resistance rate of the 9 958× 10-6 acetone is 7.55 %. As the acetone gas concentration in the range of （475 - 1 189 ） ×10-6 and （23-118 ） × 10-6, corresponding sensitivities are 1.2 × 10 -3 and 6.4 × 10 -3 %/10 -6, and the average response time is 3 min.