Nafion based solid-state gas sensors: Pd/Nafion electrodes prepared by an impregnation-reduction method in sensing oxygen

The influences of the reductant concentration of NaBH₄ and the quantity of Pd loading on the active surface area and the sensitivity of the Pd/Nafton electrodes prepared by an impregnation-reduction method in detecting oxygen were investigated in this study. The Pd/Nafion electrodes with Pd loading of 6.90 mg cm^-2 obtained at 0.006 MPd(NH₃)₄Cl₂ and 0.06 MNaBH₄ show maximum sensitivities of 0.0198 μA ppm^-1 and 0.0280 μA ppm^-1 obtained in O₂ concentration regions of 0∼5000 and 5000∼50000ppm, respectively. A sensing model was also proposed to illustrate the sensing phenomenon.