基于固态高聚物电解质一氧化碳传感器研究

Carbon monoxide sensor based on solid polymer electrolyte

以固态高聚物膜为电解质,用化学沉积法和浸渍还原法制备了金属/聚合物的复合膜电极为气敏电极,组装成分别以电流型和电位型的CO电化学传感器,研究发现传感器的稳态输出电位与CO体积分数的对数呈线性关系;应用恒电位电解技术研究电流型传感器的传感性能,按电流电压曲线确定其合适的外控电位,探讨了稳态扩散电流的产生,并在此外控电位下测定了传感器的线性应答。文中也研究了传感器的温度和湿度特性,研究表明在检测环境温度范围为30～45℃时传感器的温度系数为0.84μA/℃,从湿度特性发现在给定水蒸气分压下,输出电流与CO的体积分数之间具有线性关系,同时也随水蒸气分压增加而增大。

The electrochemical carbon monoxide sensor based on polymer solid electrolyte, which could be operated not only on amperometric mode but also on potentiometric mode, was reported. The metal/polymer composite membrane electrode served as sensing elelctrode was prepared either by a chemical deposition method or by an in situ impregnation-reduction method. It was found that there was a linear relationship between the stable output voltage of the sensor and the logarithm of the volume fraction of the CO from the research of the potentiometric sensor. The suitable manipulative voltage of the amperometric carbon monoxide sensor was studied according to the current-voltage curve and the cause of the formation of stable diffusion current was also discussed. The sensing capability such as linearity response and response time, etc, was obtained. The investigation on the temperature and humidity characteristics of the amperometric CO sensor indicated that there was a positive exponential relationship between the velocity of the CO electrochemical oxidation reaction and the Kelvin thermometric scale, and that it also had a linearity relationship between sensor sensitivity and the volume fraction of CO and by which we could gain the total progression of the electrochemical reaction of CO and O2.