EFFECTS OF SONICATION ON ELECTRODE SURFACES AND METAL PARTICLES

Ultrasonic irradiation at a frequency of 20 kHz has varying effects on electrode surfaces. Non-metals such as glassy carbon and Ebonex(TM) a re severely pitted after only a few minutes of sonication in aqueous m edia. By contrast, metals such as Pt, Au, W and Pd remain largely unda maged after 120 s, as observed by scanning electron microscopy. The ex tent of damage does not appear to be related to the melting point of t he material. By contrast, when electrodes are sonicated in suspensions of metal powders, particles are deposited onto electrode surfaces. Th e deposits were subsequently observed by scanning electron microscopy and by voltammetry. It is concluded that the ability to deposit partic les on an electrode depends on both the melting point of the particles and the electrode, whereas surface damage is more closely related to the hardness of the material.