Improvement in anti-aging of metallized Nafion® hydrogen sensors modified by chemical vapor deposition of polypyrrole

Pt/Nafion® and Pd/Nafion® electrodes were prepared by impregnation-reduction methods in detecting hydrogen. For improving their anti-aging abilities, polypyrrole (PPy) films were chemically deposited onto the metallized electrodes. After continuously aging tests for 48 h, the sensitivities of the Pt/Nafion® and the PPy-modified Pt/Nafion® electrodes decrease by 68 and 32%, respectively, but the accompanying sacrifice is the loss in sensitivity from 0.0744 to 0.0261 μA/ppm. Similarly, the sensitivities of the Pd/Nafion® and the PPy-modified Pd/Nafion® electrodes decrease by 84 and 68%, respectively, accompanying with the sacrifice of loss in sensitivity from 0.0519 to 0.0262 μA/ppm.