关键词: 传感器, CO2, 脉冲电势调制, 固体聚合物电解质, 铂黑电极

Abstract: A pulse potential-modulated technique was applied to measure the concentration of CO_2 in gas samples. In the first step, an anodic pulse and a consequent cathodic pulse were used to remove the organic pollutant and surface oxide on the surface of the platinized Pt gauze electrode before each experiment. As following, a given potential step was used to reduce the CO_2 into adsorbed intermediate on Pt surface, and the adsorbates produced were oxidized by a following anodic potential step. At same time the oxidation current of adsorbates were measured. A certain relation exists between the concentration of CO_2 and the oxidation charge within the concentration range of (0.015)% to 20%. The approximate linear concentration-charge relation appears during a shorter reduction period and at a lower concentration of CO_2. It's wide convenient and effective for the detection of CO_2 in a relatively wide concentration range.

Key words: Sensor, Carbon dioxide, Pulse potential-modulated, Solid polymer electrolyte, Pt (electrode)