Ultrasonic irradiation effect in the impregnation-reduction process of preparing Pt/Nafion (R) NH4+ sensor

A systematic study on the ultrasonic irradiation effect in the impregnation -reduction (I-R) process for preparing a Pt/Nafion(R) electrode was carried out in a flow-injection system of ammonium ion detection. Both the impregn ation and the reduction stages were affected by ultrasonic irradiation whic h increased the sensing currents of electrodes. Moreover, the effect of ult rasonic irradiation was found more significant in the reduction process tha n in the impregnation process. The relationship between sensing current and power of ultrasonic irradiation was also obtained. The specific active sur face area of the Pt/Nafion(R) electrodes were evaluated by the cyclic volta metric technique. Meanwhile, the surfaces of the electrodes were characteri zed by XRD and SEM. (C) 2001 Elsevier Science B.V. All rights reserved.