In this study, polypyrrole (PPy) and polypyrrole/molybdenum oxide composite (PPy/MoO₃) were synthesized by the chemical oxidative method in an aqueous medium, using anhydrous ferric chloride (FeCl₃) as an oxidant. The successful preparation of materials was confirmed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmittance electron microscopy (TEM). PPy and PPy/MoO₃ were converted into pellets which were used as the sensor. A four-in-line probe device was used for studying DC electrical conductivity–based ammonia vapour–sensing properties at three different ammonia concentrations, that is, 1 M, 0.5 M and 0.1 M. The PPy/MoO₃ sensor showed much-improved sensing performance than the PPy sensor in terms of % sensing response and reversibility. PPy/MoO₃ sensor showed excellent selectivity for ammonia vapours against various VOCs. The % sensing response of PPy/MoO₃ sensor towards ammonia was found to be 2.19, 2.50, 3.16, 3.87, 4.1, 5.15, 6.19, 6.55 and 7.77 times greater than ethanol, methanol, acetone, acetaldehyde, formaldehyde, toluene, benzene, chloroform and n-hexane, respectively. In the end, a sensing mechanism was also proposed, which is based on rapid adsorption–desorption of ammonia molecules on the PPy/MoO₃ sensor’s surface.

在这项研究中，聚吡咯（PPy）和聚吡咯/氧化钼复合材料（PPy/MoO ₃）在水性介质中通过化学氧化法合成，使用无水氯化铁（FeCl ₃）作为氧化剂。通过傅里叶变换红外光谱（FT-IR）、X射线衍射（XRD）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）证实了材料的成功制备。PPy 和PPy/MoO ₃被转化为颗粒，用作传感器。使用四列探针装置研究了三种不同氨浓度（即 1 M、0.5 M 和 0.1 M）下基于直流电导率的氨蒸汽传感特性。PPy/MoO ₃传感器在传感响应百分比和可逆性方面显示出比 PPy 传感器大大提高的传感性能。PPy/MoO ₃传感器对氨蒸气对各种VOCs表现出优异的选择性。发现PPy/MoO ₃传感器对氨的%传感响应是乙醇、甲醇、丙酮、乙醛、甲醛、甲苯、苯、甲醛、甲苯、苯、甲醛、甲苯、苯、甲苯、苯、甲醛、苯、甲苯、苯、甲苯、苯、甲苯、苯、甲醛、苯、甲苯、苯、甲苯、苯、甲苯、苯、甲醛、苯、甲苯、苯、甲醇、苯、甲醇、苯、甲苯、苯、苯、甲醇、苯、甲醇、苯、甲苯、苯、苯、甲醇、苯、甲醇、苯、甲醇、苯、苯、甲醇、苯、甲醇、苯、甲醇、苯、甲醇、苯、甲醇、苯、甲醇、苯、甲醇、苯、甲醇、苯、甲醇、苯、甲醇、苯、甲醇、苯、甲醇、甲醇等，其传感响应百分比分别为 2.19、2.50、3.16、3.87、4.1、5.15、6.19、6.55和 7.77 倍氯仿和ñ正己烷，分别。最后，还提出了一种传感机制，该机制基于氨分子在 PPy/MoO ₃传感器表面的快速吸附-解吸。